Relay adaptation layer configuration for a sidelink interface

ABSTRACT

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a relay user equipment (UE) may establish a sidelink unicast link with a remote UE via a sidelink signaling interface. The relay UE may identify configuration information for an adaptation layer of the sidelink signaling interface, the configuration information including at least one of: a remote UE identifier associated with the sidelink unicast link for a relay service, bearer identifier information identifying one or more bearers between the remote UE and a network entity for the relay service, a radio link control (RLC) channel mapping between a bearer identifier and one or more RLC channels, or data routing information associated with the relay service. The relay UE may relay communications between the remote UE and the network entity based at least in part on the configuration information. Numerous other aspects are described.

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wirelesscommunication and to techniques and apparatuses for a relay adaptationlayer configuration for a sidelink interface.

BACKGROUND

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources (e.g., bandwidth,transmit power, or the like). Examples of such multiple-accesstechnologies include code division multiple access (CDMA) systems, timedivision multiple access (TDMA) systems, frequency-division multipleaccess (FDMA) systems, orthogonal frequency-division multiple access(OFDMA) systems, single-carrier frequency-division multiple access(SC-FDMA) systems, time division synchronous code division multipleaccess (TD-SCDMA) systems, and Long Term Evolution (LTE).LTE/LTE-Advanced is a set of enhancements to the Universal MobileTelecommunications System (UMTS) mobile standard promulgated by theThird Generation Partnership Project (3GPP).

A wireless network may include a number of base stations (BSs) that cansupport communication for a number of user equipment (UEs). A UE maycommunicate with a BS via the downlink and uplink. The downlink (orforward link) refers to the communication link from the BS to the UE,and the uplink (or reverse link) refers to the communication link fromthe UE to the BS. As will be described in more detail herein, a BS maybe referred to as a Node B, a gNB, an access point (AP), a radio head, atransmit receive point (TRP), a New Radio (NR) BS, a 5G Node B, or thelike.

The above multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent user equipment to communicate on a municipal, national,regional, and even global level. NR, which may also be referred to as5G, is a set of enhancements to the LTE mobile standard promulgated bythe 3GPP. NR is designed to better support mobile broadband Internetaccess by improving spectral efficiency, lowering costs, improvingservices, making use of new spectrum, and better integrating with otheropen standards using orthogonal frequency division multiplexing (OFDM)with a cyclic prefix (CP) (CP-OFDM) on the downlink (DL), using CP-OFDMand/or SC-FDM (e.g., also known as discrete Fourier transform spreadOFDM (DFT-s-OFDM)) on the uplink (UL), as well as supportingbeamforming, multiple-input multiple-output (MIMO) antenna technology,and carrier aggregation. As the demand for mobile broadband accesscontinues to increase, further improvements in LTE, NR, and other radioaccess technologies remain useful.

SUMMARY

In some aspects, a method of wireless communication performed by a relayuser equipment (UE) includes establishing a sidelink unicast link with aremote UE via a sidelink signaling interface; identifying configurationinformation for an adaptation layer of the sidelink signaling interface,the configuration information including at least one of: a remote UEidentifier for the remote UE identifying the sidelink unicast linkbetween the remote UE and the relay UE for a relay service, beareridentifier information identifying one or more bearers between theremote UE and a network entity associated with the relay service, radiolink control (RLC) channel mapping information, wherein the RLC channelmapping information includes a mapping between a bearer identifier andone or more RLC channels of the sidelink unicast link and one or moreRLC channels of a link with the network entity, or data routinginformation associated with the relay service; and relayingcommunications between the remote UE and the network entity based atleast in part on the configuration information for the adaptation layerof the sidelink signaling interface.

In some aspects, a method of wireless communication performed by anetwork entity includes communicating, with a relay UE and a remote UE,configuration information for an adaptation layer of a sidelinksignaling interface between the relay UE and the remote UE, theconfiguration information including at least one of: a remote UEidentifier for the remote UE identifying a sidelink unicast link betweenthe remote UE and the relay UE for a relay service, bearer identifierinformation identifying one or more bearers between the remote UE andthe network entity associated with the relay service, RLC channelmapping information, wherein the RLC channel mapping informationincludes a mapping between a bearer identifier and one or more RLCchannels of a sidelink unicast link and one or more RLC channels of alink with the relay UE, or data routing information associated with therelay service; and communicating with the remote UE via the relay UEbased at least in part on the configuration information.

In some aspects, a method of wireless communication performed by aremote UE includes establishing a sidelink unicast link with a relay UEvia a sidelink signaling interface; receiving configuration informationfor an adaptation layer of the sidelink signaling interface, theconfiguration information including at least one of: a remote UEidentifier for the remote UE identifying the sidelink unicast linkbetween the remote UE and the relay UE for a relay service, beareridentifier information identifying one or more bearers between theremote UE and a network entity associated with the relay service, or RLCchannel mapping information, wherein the RLC channel mapping informationincludes a mapping between a bearer identifier and one or more RLCchannels of the sidelink unicast link and one or more RLC channels of alink with the network entity; and communicating with the network entityvia the relay UE based at least in part on the configurationinformation.

In some aspects, a relay UE for wireless communication includes a memoryand one or more processors operatively coupled to the memory, the memoryand the one or more processors configured to: establish a sidelinkunicast link with a remote UE via a sidelink signaling interface;identify configuration information for an adaptation layer of thesidelink signaling interface, the configuration information including atleast one of: a remote UE identifier for the remote UE identifying thesidelink unicast link between the remote UE and the relay UE for a relayservice, bearer identifier information identifying one or more bearersbetween the remote UE and a network entity associated with the relayservice, RLC channel mapping information, wherein the RLC channelmapping information includes a mapping between a bearer identifier andone or more RLC channels of the sidelink unicast link and one or moreRLC channels of a link with the network entity, or data routinginformation associated with the relay service; and relay communicationsbetween the remote UE and the network entity based at least in part onthe configuration information for the adaptation layer of the sidelinksignaling interface.

In some aspects, a network entity for wireless communication includes amemory and one or more processors operatively coupled to the memory, thememory and the one or more processors configured to: communicate, with arelay UE and a remote UE, configuration information for an adaptationlayer of a sidelink signaling interface between the relay UE and theremote UE, the configuration information including at least one of: aremote UE identifier for the remote UE identifying a sidelink unicastlink between the remote UE and the relay UE for a relay service, beareridentifier information identifying one or more bearers between theremote UE and the network entity associated with the relay service, RLCchannel mapping information, wherein the RLC channel mapping informationincludes a mapping between a bearer identifier and one or more RLCchannels of a sidelink unicast link and one or more RLC channels of alink with the relay UE, or data routing information associated with therelay service; and communicate with the remote UE via the relay UE basedat least in part on the configuration information.

In some aspects, a remote UE for wireless communication includes amemory and one or more processors operatively coupled to the memory, thememory and the one or more processors configured to: establish asidelink unicast link with a relay UE via a sidelink signalinginterface; receive configuration information for an adaptation layer ofthe sidelink signaling interface, the configuration informationincluding at least one of: a remote UE identifier for the remote UEidentifying the sidelink unicast link between the remote UE and therelay UE for a relay service, bearer identifier information identifyingone or more bearers between the remote UE and a network entityassociated with the relay service, or RLC channel mapping information,wherein the RLC channel mapping information includes a mapping between abearer identifier and one or more RLC channels of the sidelink unicastlink and one or more RLC channels of a link with the network entity; andcommunicate with the network entity via the relay UE based at least inpart on the configuration information.

In some aspects, a non-transitory computer-readable medium storing a setof instructions for wireless communication includes one or moreinstructions that, when executed by one or more processors of a relayUE, cause the relay UE to: establish a sidelink unicast link with aremote UE via a sidelink signaling interface; identify configurationinformation for an adaptation layer of the sidelink signaling interface,the configuration information including at least one of: a remote UEidentifier for the remote UE identifying the sidelink unicast linkbetween the remote UE and the relay UE for a relay service, beareridentifier information identifying one or more bearers between theremote UE and a network entity associated with the relay service, RLCchannel mapping information, wherein the RLC channel mapping informationincludes a mapping between a bearer identifier and one or more RLCchannels of the sidelink unicast link and one or more RLC channels of alink with the network entity, or data routing information associatedwith the relay service; and relay communications between the remote UEand the network entity based at least in part on the configurationinformation for the adaptation layer of the sidelink signalinginterface.

In some aspects, a non-transitory computer-readable medium storing a setof instructions for wireless communication includes one or moreinstructions that, when executed by one or more processors of a networkentity, cause the network entity to: communicate, with a relay UE and aremote UE, configuration information for an adaptation layer of asidelink signaling interface between the relay UE and the remote UE, theconfiguration information including at least one of: a remote UEidentifier for the remote UE identifying a sidelink unicast link betweenthe remote UE and the relay UE for a relay service, bearer identifierinformation identifying one or more bearers between the remote UE andthe network entity associated with the relay service, RLC channelmapping information, wherein the RLC channel mapping informationincludes a mapping between a bearer identifier and one or more RLCchannels of a sidelink unicast link and one or more RLC channels of alink with the relay UE, or data routing information associated with therelay service; and communicate with the remote UE via the relay UE basedat least in part on the configuration information.

In some aspects, a non-transitory computer-readable medium storing a setof instructions for wireless communication includes one or moreinstructions that, when executed by one or more processors of a remoteUE, cause the remote UE to: establish a sidelink unicast link with arelay UE via a sidelink signaling interface; receive configurationinformation for an adaptation layer of the sidelink signaling interface,the configuration information including at least one of: a remote UEidentifier for the remote UE identifying the sidelink unicast linkbetween the remote UE and the relay UE for a relay service, beareridentifier information identifying one or more bearers between theremote UE and a network entity associated with the relay service, or RLCchannel mapping information, wherein the RLC channel mapping informationincludes a mapping between a bearer identifier and one or more RLCchannels of the sidelink unicast link and one or more RLC channels of alink with the network entity; and communicate with the network entityvia the relay UE based at least in part on the configurationinformation.

In some aspects, an apparatus for wireless communication includes meansfor establishing a sidelink unicast link with a remote UE via a sidelinksignaling interface; means for identifying configuration information foran adaptation layer of the sidelink signaling interface, theconfiguration information including at least one of: a remote UEidentifier for the remote UE identifying the sidelink unicast linkbetween the remote UE and the apparatus for a relay service, beareridentifier information identifying one or more bearers between theremote UE and a network entity associated with the relay service, RLCchannel mapping information, wherein the RLC channel mapping informationincludes a mapping between a bearer identifier and one or more RLCchannels of the sidelink unicast link and one or more RLC channels of alink with the network entity, or data routing information associatedwith the relay service; and means for relaying communications betweenthe remote UE and the network entity based at least in part on theconfiguration information for the adaptation layer of the sidelinksignaling interface.

In some aspects, an apparatus for wireless communication includes meansfor communicating, with a relay UE and a remote UE, configurationinformation for an adaptation layer of a sidelink signaling interfacebetween the relay UE and the remote UE, the configuration informationincluding at least one of: a remote UE identifier for the remote UEidentifying a sidelink unicast link between the remote UE and the relayUE for a relay service, bearer identifier information identifying one ormore bearers between the remote UE and the apparatus associated with therelay service, RLC channel mapping information, wherein the RLC channelmapping information includes a mapping between a bearer identifier andone or more RLC channels of a sidelink unicast link and one or more RLCchannels of a link with the relay UE, or data routing informationassociated with the relay service; and means for communicating with theremote UE via the relay UE based at least in part on the configurationinformation.

In some aspects, an apparatus for wireless communication includes meansfor establishing a sidelink unicast link with a relay UE via a sidelinksignaling interface; means for receiving configuration information foran adaptation layer of the sidelink signaling interface, theconfiguration information including at least one of: a remote UEidentifier for the apparatus identifying the sidelink unicast linkbetween the apparatus and the relay UE for a relay service, beareridentifier information identifying one or more bearers between theapparatus and a network entity associated with the relay service, or RLCchannel mapping information, wherein the RLC channel mapping informationincludes a mapping between a bearer identifier and one or more RLCchannels of the sidelink unicast link and one or more RLC channels of alink with the network entity; and means for communicating with thenetwork entity via the relay UE based at least in part on theconfiguration information.

Aspects generally include a method, apparatus, system, computer programproduct, non-transitory computer-readable medium, user equipment, basestation, wireless communication device, and/or processing system assubstantially described herein with reference to and as illustrated bythe drawings and specification.

The foregoing has outlined rather broadly the features and technicaladvantages of examples according to the disclosure in order that thedetailed description that follows may be better understood. Additionalfeatures and advantages will be described hereinafter. The conceptionand specific examples disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present disclosure. Such equivalent constructions do notdepart from the scope of the appended claims. Characteristics of theconcepts disclosed herein, both their organization and method ofoperation, together with associated advantages will be better understoodfrom the following description when considered in connection with theaccompanying figures. Each of the figures is provided for the purposesof illustration and description, and not as a definition of the limitsof the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the above-recited features of the present disclosure can beunderstood in detail, a more particular description, briefly summarizedabove, may be had by reference to aspects, some of which are illustratedin the appended drawings. It is to be noted, however, that the appendeddrawings illustrate only certain typical aspects of this disclosure andare therefore not to be considered limiting of its scope, for thedescription may admit to other equally effective aspects. The samereference numbers in different drawings may identify the same or similarelements.

FIG. 1 is a diagram illustrating an example of a wireless network, inaccordance with various aspects of the present disclosure.

FIG. 2 is a diagram illustrating an example of a base station incommunication with a UE in a wireless network, in accordance withvarious aspects of the present disclosure.

FIGS. 3 and 4 are diagrams illustrating examples of a relay userequipment (UE) that relays communications between a UE and a basestation, in accordance with various aspects of the present disclosure.

FIG. 5 is a diagram illustrating examples of control-plane protocolarchitecture for a UE-to-network relay, in accordance with variousaspects of the present disclosure.

FIG. 6 is a diagram illustrating examples of user-plane protocolarchitecture for a UE-to-network relay, in accordance with variousaspects of the present disclosure.

FIG. 7 is a diagram illustrating an example of configuring a sidelinkinterface adaptation layer for a relay service, in accordance withvarious aspects of the present disclosure, in accordance with variousaspects of the present disclosure.

FIG. 8 is a diagram illustrating an example of a sidelink interfaceadaptation layer header, in accordance with various aspects of thepresent disclosure.

FIG. 9 is a diagram illustrating an example of uplink relay signaling,in accordance with various aspects of the present disclosure.

FIG. 10 is a diagram illustrating an example of downlink relaysignaling, in accordance with various aspects of the present disclosure.

FIGS. 11-13 are diagrams illustrating examples of a privacy updateprocedure, in accordance with various aspects of the present disclosure.

FIGS. 14-16 are diagrams illustrating example processes associated witha relay adaptation layer configuration for a sidelink interface, inaccordance with various aspects of the present disclosure.

FIGS. 17-19 are block diagrams of example apparatuses for wirelesscommunication, in accordance with various aspects of the presentdisclosure.

DETAILED DESCRIPTION

Various aspects of the disclosure are described more fully hereinafterwith reference to the accompanying drawings. This disclosure may,however, be embodied in many different forms and should not be construedas limited to any specific structure or function presented throughoutthis disclosure. Rather, these aspects are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope of the disclosure to those skilled in the art. Based on theteachings herein, one skilled in the art should appreciate that thescope of the disclosure is intended to cover any aspect of thedisclosure disclosed herein, whether implemented independently of orcombined with any other aspect of the disclosure. For example, anapparatus may be implemented or a method may be practiced using anynumber of the aspects set forth herein. In addition, the scope of thedisclosure is intended to cover such an apparatus or method which ispracticed using other structure, functionality, or structure andfunctionality in addition to or other than the various aspects of thedisclosure set forth herein. It should be understood that any aspect ofthe disclosure disclosed herein may be embodied by one or more elementsof a claim.

Several aspects of telecommunication systems will now be presented withreference to various apparatuses and techniques. These apparatuses andtechniques will be described in the following detailed description andillustrated in the accompanying drawings by various blocks, modules,components, circuits, steps, processes, algorithms, or the like(collectively referred to as “elements”). These elements may beimplemented using hardware, software, or combinations thereof. Whethersuch elements are implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem.

It should be noted that while aspects may be described herein usingterminology commonly associated with a 5G or NR radio access technology(RAT), aspects of the present disclosure can be applied to other RATs,such as a 3G RAT, a 4G RAT, and/or a RAT subsequent to 5G (e.g., 6G).

FIG. 1 is a diagram illustrating an example of a wireless network 100,in accordance with various aspects of the present disclosure. Thewireless network 100 may be or may include elements of a 5G (NR) networkand/or an LTE network, among other examples. The wireless network 100may include a number of base stations 110 (shown as BS 110 a, BS 110 b,BS 110 c, and BS 110 d) and other network entities. A base station (BS)is an entity that communicates with user equipment (UEs) and may also bereferred to as an NR BS, a Node B, a gNB, a 5G node B (NB), an accesspoint, a transmit receive point (TRP), or the like. Each BS may providecommunication coverage for a particular geographic area. In 3GPP, theterm “cell” can refer to a coverage area of a BS and/or a BS subsystemserving this coverage area, depending on the context in which the termis used.

A BS may provide communication coverage for a macro cell, a pico cell, afemto cell, and/or another type of cell. A macro cell may cover arelatively large geographic area (e.g., several kilometers in radius)and may allow unrestricted access by UEs with service subscription. Apico cell may cover a relatively small geographic area and may allowunrestricted access by UEs with service subscription. A femto cell maycover a relatively small geographic area (e.g., a home) and may allowrestricted access by UEs having association with the femto cell (e.g.,UEs in a closed subscriber group (CSG)). A BS for a macro cell may bereferred to as a macro BS. A BS for a pico cell may be referred to as apico BS. A BS for a femto cell may be referred to as a femto BS or ahome BS. In the example shown in FIG. 1 , a BS 110 a may be a macro BSfor a macro cell 102 a, a BS 110 b may be a pico BS for a pico cell 102b, and a BS 110 c may be a femto BS for a femto cell 102 c. A BS maysupport one or multiple (e.g., three) cells. The terms “eNB”, “basestation”, “NR BS”, “gNB”, “TRP”, “AP”, “node B”, “5G NB”, and “cell” maybe used interchangeably herein.

In some aspects, a cell may not necessarily be stationary, and thegeographic area of the cell may move according to the location of amobile BS. In some aspects, the BSs may be interconnected to one anotherand/or to one or more other BSs or network nodes (not shown) in thewireless network 100 through various types of backhaul interfaces, suchas a direct physical connection or a virtual network, using any suitabletransport network.

Wireless network 100 may also include relay stations. A relay station isan entity that can receive a transmission of data from an upstreamstation (e.g., a BS or a UE) and send a transmission of the data to adownstream station (e.g., a UE or a BS). A relay station may also be aUE that can relay transmissions for other UEs. In the example shown inFIG. 1 , a relay BS 110 d may communicate with macro BS 110 a and a UE120 d in order to facilitate communication between BS 110 a and UE 120d. A relay BS may also be referred to as a relay station, a relay basestation, a relay, or the like.

Wireless network 100 may be a heterogeneous network that includes BSs ofdifferent types, such as macro BSs, pico BSs, femto BSs, relay BSs, orthe like. These different types of BSs may have different transmit powerlevels, different coverage areas, and different impacts on interferencein wireless network 100. For example, macro BSs may have a high transmitpower level (e.g., 5 to 40 watts) whereas pico BSs, femto BSs, and relayBSs may have lower transmit power levels (e.g., 0.1 to 2 watts).

A network controller 130 may couple to a set of BSs and may providecoordination and control for these BSs. Network controller 130 maycommunicate with the BSs via a backhaul. The BSs may also communicatewith one another, directly or indirectly, via a wireless or wirelinebackhaul.

UEs 120 (e.g., 120 a, 120 b, 120 c) may be dispersed throughout wirelessnetwork 100, and each UE may be stationary or mobile. A UE may also bereferred to as an access terminal, a terminal, a mobile station, asubscriber unit, a station, or the like. A UE may be a cellular phone(e.g., a smart phone), a personal digital assistant (PDA), a wirelessmodem, a wireless communication device, a handheld device, a laptopcomputer, a cordless phone, a wireless local loop (WLL) station, atablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook,a medical device or equipment, biometric sensors/devices, wearabledevices (smart watches, smart clothing, smart glasses, smart wristbands, smart jewelry (e.g., smart ring, smart bracelet)), anentertainment device (e.g., a music or video device, or a satelliteradio), a vehicular component or sensor, smart meters/sensors,industrial manufacturing equipment, a global positioning system device,or any other suitable device that is configured to communicate via awireless or wired medium.

Some UEs may be considered machine-type communication (MTC) or evolvedor enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEsinclude, for example, robots, drones, remote devices, sensors, meters,monitors, and/or location tags, that may communicate with a basestation, another device (e.g., remote device), or some other entity. Awireless node may provide, for example, connectivity for or to a network(e.g., a wide area network such as Internet or a cellular network) via awired or wireless communication link. Some UEs may be consideredInternet-of-Things (IoT) devices, and/or may be implemented as NB-IoT(narrowband internet of things) devices. Some UEs may be considered aCustomer Premises Equipment (CPE). UE 120 may be included inside ahousing that houses components of UE 120, such as processor componentsand/or memory components. In some aspects, the processor components andthe memory components may be coupled together. For example, theprocessor components (e.g., one or more processors) and the memorycomponents (e.g., a memory) may be operatively coupled, communicativelycoupled, electronically coupled, and/or electrically coupled.

In general, any number of wireless networks may be deployed in a givengeographic area. Each wireless network may support a particular RAT andmay operate on one or more frequencies. A RAT may also be referred to asa radio technology, an air interface, or the like. A frequency may alsobe referred to as a carrier, a frequency channel, or the like. Eachfrequency may support a single RAT in a given geographic area in orderto avoid interference between wireless networks of different RATs. Insome cases, NR or 5G RAT networks may be deployed.

In some aspects, two or more UEs 120 (e.g., shown as UE 120 a and UE 120e) may communicate directly using one or more sidelink channels (e.g.,without using a base station 110 as an intermediary to communicate withone another). For example, the UEs 120 may communicate usingpeer-to-peer (P2P) communications, device-to-device (D2D)communications, a vehicle-to-everything (V2X) protocol (e.g., which mayinclude a vehicle-to-vehicle (V2V) protocol or avehicle-to-infrastructure (V2I) protocol), and/or a mesh network. Inthis case, the UE 120 may perform scheduling operations, resourceselection operations, and/or other operations described elsewhere hereinas being performed by the base station 110.

Devices of wireless network 100 may communicate using theelectromagnetic spectrum, which may be subdivided based on frequency orwavelength into various classes, bands, channels, or the like. Forexample, devices of wireless network 100 may communicate using anoperating band having a first frequency range (FR1), which may span from410 MHz to 7.125 GHz, and/or may communicate using an operating bandhaving a second frequency range (FR2), which may span from 24.25 GHz to52.6 GHz. The frequencies between FR1 and FR2 are sometimes referred toas mid-band frequencies. Although a portion of FR1 is greater than 6GHz, FR1 is often referred to as a “sub-6 GHz” band. Similarly, FR2 isoften referred to as a “millimeter wave” band despite being differentfrom the extremely high frequency (EHF) band (30 GHz-300 GHz) which isidentified by the International Telecommunications Union (ITU) as a“millimeter wave” band. Thus, unless specifically stated otherwise, itshould be understood that the term “sub-6 GHz” or the like, if usedherein, may broadly represent frequencies less than 6 GHz, frequencieswithin FR1, and/or mid-band frequencies (e.g., greater than 7.125 GHz).Similarly, unless specifically stated otherwise, it should be understoodthat the term “millimeter wave” or the like, if used herein, may broadlyrepresent frequencies within the EHF band, frequencies within FR2,and/or mid-band frequencies (e.g., less than 24.25 GHz). It iscontemplated that the frequencies included in FR1 and FR2 may bemodified, and techniques described herein are applicable to thosemodified frequency ranges.

As indicated above, FIG. 1 is provided as an example. Other examples maydiffer from what is described with regard to FIG. 1 .

FIG. 2 is a diagram illustrating an example 200 of a base station 110 incommunication with a UE 120 in a wireless network 100. Base station 110may be equipped with T antennas 234 a through 234 t, and UE 120 may beequipped with R antennas 252 a through 252 r, where in general T≥1 andR≥1.

At base station 110, a transmit processor 220 may receive data from adata source 212 for one or more UEs, select one or more modulation andcoding schemes (MCS) for each UE based at least in part on channelquality indicators (CQIs) received from the UE, process (e.g., encodeand modulate) the data for each UE based at least in part on the MCS(s)selected for the UE, and provide data symbols for all UEs. Transmitprocessor 220 may also process system information (e.g., for semi-staticresource partitioning information (SRPI)) and control information (e.g.,CQI requests, grants, and/or upper layer signaling) and provide overheadsymbols and control symbols. Transmit processor 220 may also generatereference symbols for reference signals (e.g., a cell-specific referencesignal (CRS) or a demodulation reference signal (DMRS)) andsynchronization signals (e.g., a primary synchronization signal (PSS) ora secondary synchronization signal (SSS)). A transmit (TX)multiple-input multiple-output (MIMO) processor 230 may perform spatialprocessing (e.g., precoding) on the data symbols, the control symbols,the overhead symbols, and/or the reference symbols, if applicable, andmay provide T output symbol streams to T modulators (MODs) 232 a through232 t. Each modulator 232 may process a respective output symbol stream(e.g., for OFDM) to obtain an output sample stream. Each modulator 232may further process (e.g., convert to analog, amplify, filter, andupconvert) the output sample stream to obtain a downlink signal. Tdownlink signals from modulators 232 a through 232 t may be transmittedvia T antennas 234 a through 234 t, respectively.

At UE 120, antennas 252 a through 252 r may receive the downlink signalsfrom base station 110 and/or other base stations and may providereceived signals to demodulators (DEMODs) 254 a through 254 r,respectively. Each demodulator 254 may condition (e.g., filter, amplify,downconvert, and digitize) a received signal to obtain input samples.Each demodulator 254 may further process the input samples (e.g., forOFDM) to obtain received symbols. A MIMO detector 256 may obtainreceived symbols from all R demodulators 254 a through 254 r, performMIMO detection on the received symbols if applicable, and providedetected symbols. A receive processor 258 may process (e.g., demodulateand decode) the detected symbols, provide decoded data for UE 120 to adata sink 260, and provide decoded control information and systeminformation to a controller/processor 280. The term“controller/processor” may refer to one or more controllers, one or moreprocessors, or a combination thereof. A channel processor may determinea reference signal received power (RSRP) parameter, a received signalstrength indicator (RSSI) parameter, a reference signal received quality(RSRQ) parameter, and/or a channel quality indicator (CQI) parameter,among other examples. In some aspects, one or more components of UE 120may be included in a housing 284.

Network controller 130 may include communication unit 294,controller/processor 290, and memory 292. Network controller 130 mayinclude, for example, one or more devices in a core network. Networkcontroller 130 may communicate with base station 110 via communicationunit 294.

Antennas (e.g., antennas 234 a through 234 t and/or antennas 252 athrough 252 r) may include, or may be included within, one or moreantenna panels, antenna groups, sets of antenna elements, and/or antennaarrays, among other examples. An antenna panel, an antenna group, a setof antenna elements, and/or an antenna array may include one or moreantenna elements. An antenna panel, an antenna group, a set of antennaelements, and/or an antenna array may include a set of coplanar antennaelements and/or a set of non-coplanar antenna elements. An antennapanel, an antenna group, a set of antenna elements, and/or an antennaarray may include antenna elements within a single housing and/orantenna elements within multiple housings. An antenna panel, an antennagroup, a set of antenna elements, and/or an antenna array may includeone or more antenna elements coupled to one or more transmission and/orreception components, such as one or more components of FIG. 2 .

On the uplink, at UE 120, a transmit processor 264 may receive andprocess data from a data source 262 and control information (e.g., forreports that include RSRP, RSSI, RSRQ, and/or CQI) fromcontroller/processor 280. Transmit processor 264 may also generatereference symbols for one or more reference signals. The symbols fromtransmit processor 264 may be precoded by a TX MIMO processor 266 ifapplicable, further processed by modulators 254 a through 254 r (e.g.,for DFT-s-OFDM or CP-OFDM), and transmitted to base station 110. In someaspects, a modulator and a demodulator (e.g., MOD/DEMOD 254) of the UE120 may be included in a modem of the UE 120. In some aspects, the UE120 includes a transceiver. The transceiver may include any combinationof antenna(s) 252, modulators and/or demodulators 254, MIMO detector256, receive processor 258, transmit processor 264, and/or TX MIMOprocessor 266. The transceiver may be used by a processor (e.g.,controller/processor 280) and memory 282 to perform aspects of any ofthe methods described herein, for example, as described with referenceto FIGS. 7, 8, 9, 10, 11, 12, 13, 14, 15 , and/or 16.

At base station 110, the uplink signals from UE 120 and other UEs may bereceived by antennas 234, processed by demodulators 232, detected by aMIMO detector 236 if applicable, and further processed by a receiveprocessor 238 to obtain decoded data and control information sent by UE120. Receive processor 238 may provide the decoded data to a data sink239 and the decoded control information to controller/processor 240.Base station 110 may include communication unit 244 and communicate tonetwork controller 130 via communication unit 244. Base station 110 mayinclude a scheduler 246 to schedule UEs 120 for downlink and/or uplinkcommunications. In some aspects, a modulator and a demodulator (e.g.,MOD/DEMOD 232) of the base station 110 may be included in a modem of thebase station 110. In some aspects, the base station 110 includes atransceiver. The transceiver may include any combination of antenna(s)234, modulators and/or demodulators 232, MIMO detector 236, receiveprocessor 238, transmit processor 220, and/or TX MIMO processor 230. Thetransceiver may be used by a processor (e.g., controller/processor 240)and memory 242 to perform aspects of any of the methods describedherein, for example, as described with reference to FIGS. 7, 8, 9, 10,11, 12, 13, 14, 15 , and/or 16.

Controller/processor 240 of base station 110, controller/processor 280of UE 120, and/or any other component(s) of FIG. 2 may perform one ormore techniques associated with relay adaptation layer configuration fora sidelink interface, as described in more detail elsewhere herein. Insome aspects, the network entity described herein is the base station110, is included in the base station 110, or includes one or morecomponents of the base station 110 shown in FIG. 2 . For example,controller/processor 240 of base station 110, controller/processor 280of UE 120, and/or any other component(s) of FIG. 2 may perform or directoperations of, for example, process 1400 of FIG. 14 , process 1500 ofFIG. 15 , process 1600 of FIG. 16 , and/or other processes as describedherein. Memories 242 and 282 may store data and program codes for basestation 110 and UE 120, respectively. In some aspects, memory 242 and/ormemory 282 may include a non-transitory computer-readable medium storingone or more instructions (e.g., code and/or program code) for wirelesscommunication. For example, the one or more instructions, when executed(e.g., directly, or after compiling, converting, and/or interpreting) byone or more processors of the base station 110 and/or the UE 120, maycause the one or more processors, the UE 120, and/or the base station110 to perform or direct operations of, for example, process 1400 ofFIG. 14 , process 1500 of FIG. 15 , process 1600 of FIG. 16 , and/orother processes as described herein. In some aspects, executinginstructions may include running the instructions, converting theinstructions, compiling the instructions, and/or interpreting theinstructions, among other examples.

In some aspects, the UE 120 (e.g., a relay UE) includes means forestablishing a sidelink unicast link with a remote UE via a sidelinksignaling interface; means for identifying configuration information foran adaptation layer of the sidelink signaling interface, theconfiguration information including at least one of: a remote UEidentifier for the remote UE identifying the sidelink unicast linkbetween the remote UE and the relay UE for a relay service, beareridentifier information identifying one or more bearers between theremote UE and a network entity associated with the relay service, radiolink control (RLC) channel mapping information, wherein the RLC channelmapping information includes a mapping between a bearer identifier andone or more RLC channels of the sidelink unicast link and one or moreRLC channels of a link with the network entity, or data routinginformation associated with the relay service; and/or means for relayingcommunications between the remote UE and the network entity based atleast in part on the configuration information for the adaptation layerof the sidelink signaling interface. The means for the relay UE 120 toperform operations described herein may include, for example, one ormore of antenna 252, demodulator 254, MIMO detector 256, receiveprocessor 258, transmit processor 264, TX MIMO processor 266, modulator254, controller/processor 280, or memory 282.

In some aspects, the relay UE 120 includes means for assigning remote UEidentifiers to each remote UE, of a plurality of remote UEs, incommunication with the relay UE.

In some aspects, the relay UE 120 includes means for assigning theremote UE identifier to the remote UE including a unique indexassociated with the sidelink unicast link; and/or means fortransmitting, to the remote UE, an indication of the remote UEidentifier via a sidelink signaling interface message.

In some aspects, the relay UE 120 includes means for assigning a uniqueindex associated with the sidelink unicast link; and/or means fortransmitting information indicating the unique index to the networkentity via a radio resource control message.

In some aspects, the relay UE 120 includes means for receiving, from thenetwork entity, a relaying configuration indicating at least part of theconfiguration information.

In some aspects, the relay UE 120 includes means for receiving, from thenetwork entity, an indication of the remote UE identifier via a radioresource control message.

In some aspects, the relay UE 120 includes means for receiving, from thenetwork entity, an indication of remote UE identifiers for each remoteUE, of a plurality of remote UEs, in communication with the relay UE.

In some aspects, the relay UE 120 includes means for receiving, from thenetwork entity, an indication of a cell radio network temporaryidentifier (C-RNTI) for each remote UE, of a plurality of remote UEs, incommunication with the relay UE.

In some aspects, the relay UE 120 includes means for receiving, from thenetwork entity, an indication of a temporary identifier for each remoteUE, of a plurality of remote UEs, in communication with the relay UE,wherein the temporary identifier is unique among the plurality of remoteUEs in communication with the relay UE.

In some aspects, the relay UE 120 includes means for receiving, from thenetwork entity, the bearer identifier information including anindication of a bearer identifier identifying a bearer between theremote UE and the network entity associated with the relay service,wherein the bearer identifier is the same as a data radio bearer (DRB)identifier of a DRB between the remote UE and the network entity or thesame as a signaling radio bearer (SRB) identifier of an SRB between theremote UE and the network entity.

In some aspects, the relay UE 120 includes means for receiving, from thenetwork entity, the bearer identifier information including anindication of a bearer identifier identifying a bearer between theremote UE and the network entity associated with the relay service,wherein the bearer identifier is a unique identifier associated with thebearer between the remote UE and the network entity to be used with therelay service.

In some aspects, the relay UE 120 includes means for receiving, from thenetwork entity, an indication of a default bearer identifier identifyingan SRB associated with radio resource control messages.

In some aspects, the relay UE 120 includes means for receiving, from theremote UE via the sidelink unicast link, a radio resource control setuprequest message, wherein the radio resource control setup requestmessage includes the default bearer identifier; means for determiningthat the radio resource control setup request message is to betransmitted using the SRB associated with radio resource controlmessages based at least in part on the default bearer identifier; and/ormeans for relaying the radio resource control setup request message tothe network entity via an RLC channel for the SRB associated with radioresource control messages.

In some aspects, the relay UE 120 includes means for receiving, from thenetwork entity, a relaying configuration via a radio resource controlmessage indicating the bearer identifier based at least in part onrelaying the radio resource control setup request message to the networkentity; and/or means for relaying the radio resource control messageindicating the bearer identifier to the remote UE based at least in parton the relaying configuration.

In some aspects, the relay UE 120 includes means for receiving, from theremote UE via the sidelink unicast link, a packet data convergenceprotocol (PDCP) packet data unit (PDU) that includes an adaptation layerheader that indicates at least one of: the remote UE identifierassociated with the remote UE, or a bearer identifier; means foridentifying an RLC channel of the link with the network entity based atleast in part on the RLC channel mapping information and the beareridentifier; means for generating a Uu PDCP PDU for the link with thenetwork entity that includes an adaptation layer header that indicatesat least one of: the remote UE identifier associated with the remote UE,or the bearer identifier; and/or means for transmitting, to the networkentity via the RLC channel, the Uu PDCP PDU for the link with thenetwork entity that includes the adaptation layer header.

In some aspects, the relay UE 120 includes means for receiving, from thenetwork entity, a Uu PDCP PDU that includes an adaptation layer headerthat indicates at least one of: the remote UE identifier associated withthe remote UE, or a bearer identifier; means for identifying an RLCchannel of the sidelink unicast link based at least in part on the RLCchannel mapping information and the bearer identifier; means forgenerating a PDCP PDU for the sidelink unicast link that includes anadaptation layer header that indicates at least one of: the remote UEidentifier associated with the remote UE, or the bearer identifier;and/or means for transmitting, to the remote UE via the RLC channel, thePDCP PDU for the sidelink unicast link that includes the adaptationlayer header.

In some aspects, the relay UE 120 includes means for performing aprivacy update procedure with at least one of the remote UE or thenetwork entity, wherein the privacy update procedure includes updatinginformation included in configuration information. In some aspects, therelay UE 120 includes means for performing the privacy update procedureaccording to a periodic schedule. In some aspects, the relay UE 120includes means for detecting a trigger event associated with a privacyupdate; and/or means for performing the privacy update procedure basedat least in part on detecting the trigger event.

In some aspects, the relay UE 120 includes means for modifying theremote UE identifier for the remote UE to a modified remote UEidentifier; means for communicating, with the remote UE via the sidelinkunicast link, to indicate the modified remote UE identifier; and/ormeans for communicating, with the network entity, to indicate themodified remote UE identifier.

In some aspects, the relay UE 120 includes means for receiving, from thenetwork entity, an indication of modified identifier information for atleast one of the adaptation layer of the sidelink signaling interface orthe adaption layer of the link with the network entity; means formodifying the configuration information based at least in part on themodified identifier information; means for communicating, with theremote UE via the sidelink unicast link, to indicate the modifiedidentifier information; and/or means for communicating, with the networkentity, to indicate that the configuration information for the sidelinksignaling interface has been modified at the relay UE and the remote UEbased at least in part on communicating with the remote UE to indicatethe modified identifier information.

In some aspects, the relay UE 120 includes means for receiving, from theremote UE, a signal that includes a previous identifier, that ismodified by the modified identifier information to a modifiedidentifier, in an adaptation layer header of the signal after receivingthe indication of the modified identifier information and prior toreceiving a signal that includes an indication of the modifiedidentifier; and/or means for relaying, to the network entity via an RLCchannel, the signal based at least in part on the previous identifier.

In some aspects, the relay UE 120 includes means for receiving, from theremote UE or the network entity, a signal that includes an indication ofa modified identifier, indicated in the modified identifier information,in an adaptation layer header of the signal; and/or means for refrainingfrom relaying communications using a previous identifier based at leastin part on receiving the signal that includes the indication of themodified identifier in the adaptation layer header of the signal.

In some aspects, a network entity (e.g., a base station 110 or anothernetwork entity) includes means for communicating, with a relay UE and aremote UE, configuration information for an adaptation layer of asidelink signaling interface between the relay UE and the remote UE, theconfiguration information including at least one of: a remote UEidentifier for the remote UE identifying a sidelink unicast link betweenthe remote UE and the relay UE for a relay service, bearer identifierinformation identifying one or more bearers between the remote UE andthe network entity associated with the relay service, RLC channelmapping information, wherein the RLC channel mapping informationincludes a mapping between a bearer identifier and one or more RLCchannels of a sidelink unicast link and one or more RLC channels of alink with the relay UE, or data routing information associated with therelay service; and/or means for communicating with the remote UE via therelay UE based at least in part on the configuration information. Insome aspects, the means for the network entity to perform operationsdescribed herein may include, for example, one or more of transmitprocessor 220, TX MIMO processor 230, modulator 232, antenna 234,demodulator 232, MIMO detector 236, receive processor 238,controller/processor 240, memory 242, or scheduler 246.

In some aspects, the network entity includes means for receiving, fromthe relay UE, an indication of remote UE identifiers for each remote UE,of a plurality of remote UEs, in communication with the relay UE via aradio resource control message.

In some aspects, the network entity includes means for assigning remoteUE identifiers to each remote UE, of a plurality of remote UEs, incommunication with the relay UE.

In some aspects, the network entity includes means for assigning, for aremote UE of the plurality of remote UEs, the remote UE identifier as aC-RNTI identifying a sidelink unicast link between the remote UE and therelay UE.

In some aspects, the network entity includes means for assigning, for aremote UE of the plurality of remote UEs, a temporary identifier for theremote UE, wherein the temporary identifier is unique among theplurality of remote UEs in communication with the relay UE.

In some aspects, the network entity includes means for transmitting, tothe remote UE via the relay UE, an indication of the remote UEidentifier for the remote UE via a radio resource control message.

In some aspects, the network entity includes means for transmitting, tothe relay UE, a relaying configuration via a radio resource controlmessage, wherein the relaying configuration indicates the remote UEidentifiers for each remote UE, of the plurality of remote UEs, incommunication with the relay UE.

In some aspects, the network entity includes means for assigning abearer identifier for each bearer of the one or more bearers between theremote UE and a network entity associated with the relay service.

In some aspects, the network entity includes means for transmitting, tothe remote UE via the relay UE, the bearer identifier information via aradio resource control message, wherein the bearer identifierinformation indicates:

In some aspects, the network entity includes means for transmitting, tothe relay UE, the bearer identifier information via a radio resourcecontrol message, wherein the bearer identifier information indicates:

In some aspects, the network entity includes means for transmitting, tothe relay UE and the remote UE via the relay UE, an indication of adefault bearer identifier identifying an SRB associated with radioresource control messages.

In some aspects, the network entity includes means for receiving, fromthe relay UE, an adaptation layer PDU; means for determining an SRB or aDRB associated with the remote UE based at least in part on a header ofthe adaptation layer PDU; means for removing the header of theadaptation layer PDU; and/or means for transferring a New Radio PDCP PDUof the adaptation layer PDU to an upper layer.

In some aspects, the network entity includes means for determining theremote UE identifier of the remote UE associated with a sidelink unicastlink for the remote UE; means for determining a bearer identifier of theremote UE corresponding to a radio access bearer of the remote UE; meansfor determining a radio access RLC channel between the relay UE and thenetwork entity corresponding to the bearer identifier; means forgenerating an adaptation layer header including at least one of theremote UE identifier, the bearer identifier, or a path identifier;and/or means for transmitting, to the relay UE, an adaptation layer PDUwith the adaptation layer header on the radio access RLC channel betweenthe relay UE and the network entity.

In some aspects, the network entity includes means for performing aprivacy update procedure with at least one of the remote UE or the relayUE, wherein the privacy update procedure includes updating informationincluded in configuration information. In some aspects, the networkentity includes means for performing the privacy update procedureaccording to a periodic schedule. In some aspects, the network entityincludes means for detecting a trigger event associated with a privacyupdate; and/or means for performing the privacy update procedure basedat least in part on detecting the trigger event.

In some aspects, the network entity includes means for modifying one ormore identifiers for an adaption layer header for the relay service;means for communicating, with the remote UE via the relay UE, toindicate modified identifier information that indicates the one or moremodified identifiers; and/or means for communicating, with the relay UE,to indicate the modified identifier information that indicates the oneor more modified identifiers.

In some aspects, the UE 120 (e.g., a remote UE) includes means forestablishing a sidelink unicast link with a relay UE via a sidelinksignaling interface; means for receiving configuration information foran adaptation layer of the sidelink signaling interface, theconfiguration information including at least one of: a remote UEidentifier for the remote UE identifying the sidelink unicast linkbetween the remote UE and the relay UE for a relay service, beareridentifier information identifying one or more bearers between theremote UE and a network entity associated with the relay service, or RLCchannel mapping information, wherein the RLC channel mapping informationincludes a mapping between a bearer identifier and one or more RLCchannels of the sidelink unicast link and one or more RLC channels of alink with the network entity; and/or means for communicating with thenetwork entity via the relay UE based at least in part on theconfiguration information. The means for the remote UE 120 to performoperations described herein may include, for example, one or more ofantenna 252, demodulator 254, MIMO detector 256, receive processor 258,transmit processor 264, TX MIMO processor 266, modulator 254,controller/processor 280, or memory 282.

In some aspects, the remote UE 120 includes means for receiving, fromthe relay UE, an indication of the remote UE identifier for the remoteUE.

In some aspects, the remote UE 120 includes means for receiving, fromthe network entity via the relay UE, an indication of the remote UEidentifier for the remote UE via a radio resource control message.

In some aspects, the remote UE 120 includes means for assigning a beareridentifier for each bearer of the one or more bearers between the remoteUE and a network entity associated with the relay service.

In some aspects, the remote UE 120 includes means for receiving, fromthe network entity via the relay UE, the bearer identifier informationvia a radio resource control message, wherein the bearer identifierinformation indicates:

In some aspects, the remote UE 120 includes means for receiving, fromthe network entity via the relay UE, an indication of a default beareridentifier identifying an SRB) associated with radio resource controlmessages.

In some aspects, the remote UE 120 includes means for transmitting, tothe network entity via the relay UE, a resource control messageincluding the default bearer identifier identifying the SRB associatedwith radio resource control messages.

In some aspects, the remote UE 120 includes means for receiving, fromthe relay UE, an adaptation layer PDU; means for determining an SRB or aDRB associated with the remote UE based at least in part on a header ofthe adaptation layer PDU; means for removing the header of theadaptation layer PDU; and/or means for transferring a New Radio PDCP PDUof the adaptation layer PDU to an upper layer.

In some aspects, the remote UE 120 includes means for determining theremote UE identifier of the remote UE associated with the sidelinkunicast link for the remote UE; means for determining a beareridentifier of the remote UE corresponding to a radio access bearer ofthe remote UE; means for determining a sidelink RLC channel between therelay UE and the remote UE corresponding to the bearer identifier; meansfor generating an adaptation layer header including at least one of theremote UE identifier, the bearer identifier, or a path identifier;and/or means for transmitting, to the relay UE, an adaptation layer PDUwith the adaptation layer header on the sidelink RLC channel between therelay UE and the remote UE.

In some aspects, the remote UE 120 includes means for performing aprivacy update procedure with at least one of the network entity or therelay UE, wherein the privacy update procedure includes updatinginformation included in configuration information. In some aspects, theremote UE 120 includes means for performing the privacy update procedureaccording to a periodic schedule. In some aspects, the remote UE 120includes means for detecting a trigger event associated with a privacyupdate; and/or means for performing the privacy update procedure basedat least in part on detecting the trigger event.

In some aspects, the remote UE 120 includes means for receiving, fromthe network entity via the relay UE or from the relay UE, an indicationof modified identifier information indicating one or more modifiedidentifiers for the adaptation layer; means for modifying theconfiguration information based at least in part on the modifiedidentifier information; and/or means for communicating, with the relayUE, to indicate that the one or more modified identifiers for theadaptation layer been modified at the remote UE.

While blocks in FIG. 2 are illustrated as distinct components, thefunctions described above with respect to the blocks may be implementedin a single hardware, software, or combination component or in variouscombinations of components. For example, the functions described withrespect to the transmit processor 264, the receive processor 258, and/orthe TX MIMO processor 266 may be performed by or under the control ofcontroller/processor 280.

As indicated above, FIG. 2 is provided as an example. Other examples maydiffer from what is described with regard to FIG. 2 .

FIG. 3 is a diagram illustrating an example 300 of a relay UE thatrelays communications between a UE and a base station. As shown, example300 includes a UE 305, a relay UE 310, and a base station 110. Inexample 300, the UE 305 is an Rx UE, and the relay UE 310 is a Tx UE. Insome aspects, the UE 305 is one UE 120, and the relay UE 310 is anotherUE 120. In some aspects, the UE 305 may be referred to as a remote UE.

As shown in FIG. 3 , the UE 305 may receive a communication (e.g., dataand/or control information) directly from the base station 110 as adownlink communication 315. Additionally, or alternatively, the UE 305may receive a communication (e.g., data and/or control information)indirectly from the base station 110 via the relay UE 310. For example,the base station 110 may transmit the communication to the relay UE 310as a downlink communication 320, and the relay UE 310 may relay (e.g.,forward or transmit) the communication to the UE 305 as a sidelinkcommunication 325.

In some aspects, the UE 305 may communicate directly with the basestation 110 via a direct link 330. For example, the downlinkcommunication 315 may be transmitted via the direct link 330. Acommunication transmitted via the direct link 330 between the UE 305 andthe base station 110 (e.g., in the downlink communication 315) does notpass through and is not relayed by the relay UE 310. In some aspects,the UE 305 may communicate indirectly with the base station 110 via anindirect link 335. For example, the downlink communication 320 and thesidelink communication 325 may be transmitted via different segments ofthe indirect link 335. A communication transmitted via the indirect link335 between the UE 305 and the base station 110 (e.g., in the downlinkcommunication 320 and the sidelink communication 325) passes through andis relayed by the relay UE 310. Using the communication scheme shown inFIG. 3 may improve network performance and increase reliability byproviding the UE 305 with link diversity for communicating with the basestation 110.

In some cases, the UE 305 may receive a communication (e.g., the samecommunication) from the base station 110 via both the direct link 330and the indirect link 335. In other cases, the base station 110 mayselect one of the links (e.g., either the direct link 330 or theindirect link 335), and may transmit a communication to the UE 305 usingonly the selected link. Alternatively, the base station 110 may receivean indication of one of the links (e.g., either the direct link 330 orthe indirect link 335), and may transmit a communication to the UE 305using only the indicated link. The indication may be transmitted by theUE 305 and/or the relay UE 310. In some aspects, such selection and/orindication may be based at least in part on channel conditions and/orlink reliability.

As indicated above, FIG. 3 is provided as an example. Other examples maydiffer from what is described with respect to FIG. 3 .

FIG. 4 is a diagram illustrating an example 400 of a relay UE thatrelays communications between a UE and a base station. As shown, example400 includes a UE 405, a relay UE 410, and a base station 110. Inexample 400, the UE 405 is a Tx UE, and the relay UE 410 is an Rx UE. Insome aspects, the UE 405 is one UE 120, and the relay UE 410 is anotherUE 120. In some aspects, the UE 405 may be referred to as a remote UE.

As shown in FIG. 4 , the UE 405 may transmit a communication (e.g., dataand/or control information) directly to the base station 110 as anuplink communication 415. Additionally, or alternatively, the UE 405 maytransmit a communication (e.g., data and/or control information)indirectly to the base station 110 via the relay UE 410. For example,the UE 405 may transmit the communication to the relay UE 410 as asidelink communication 420, and the relay UE 410 may relay (e.g.,forward or transmit) the communication to the base station 110 as anuplink communication 425.

In some aspects, the UE 405 may communicate directly with the basestation 110 via a direct link 430. For example, the uplink communication415 may be transmitted via the direct link 430. A communicationtransmitted via the direct link 430 between the UE 405 and the basestation 110 (e.g., in the uplink communication 415) does not passthrough and is not relayed by the relay UE 410. In some aspects, the UE405 may communicate indirectly with the base station 110 via an indirectlink 435. For example, the sidelink communication 420 and the uplinkcommunication 425 may be transmitted via different segments of theindirect link 435. A communication transmitted via the indirect link 435between the UE 405 and the base station 110 (e.g., in the sidelinkcommunication 420 and the uplink communication 425) passes through andis relayed by the relay UE 410.

Using the communication scheme shown in FIG. 4 may improve networkperformance and increase reliability by providing the UE 405 with linkdiversity for communicating with the base station 110. For millimeterwave (e.g., frequency range 2, or FR2) communications, which aresusceptible to link blockage and link impairment, this link diversitymay improve reliability and prevent multiple retransmissions of datathat may otherwise be retransmitted in order to achieve a successfulcommunication. However, techniques described herein are not limited tomillimeter wave communications, and may be used for sub-6 gigahertz(e.g., frequency range 1, or FR1) communications.

In some cases, the UE 405 may transmit a communication (e.g., the samecommunication) to the base station 110 via both the direct link 430 andthe indirect link 435. In other cases, the UE 405 may select one of thelinks (e.g., either the direct link 430 or the indirect link 435), andmay transmit a communication to the base station 110 using only theselected link. Alternatively, the UE 405 may receive an indication ofone of the links (e.g., either the direct link 430 or the indirect link435), and may transmit a communication to the base station 110 usingonly the indicated link. The indication may be transmitted by the basestation 110 and/or the relay UE 410. In some aspects, such selectionand/or indication may be based at least in part on channel conditionsand/or link reliability.

As indicated above, FIG. 4 is provided as an example. Other examples maydiffer from what is described with respect to FIG. 4 .

FIG. 5 is a diagram illustrating examples of control-plane protocolarchitecture 500 and 505 for a UE-to-network relay. As shown in FIG. 5 ,the control-plane protocol architecture 500 and 505 may correspond to aremote UE (e.g., UE 120) and a relay UE (e.g., UE 120).

As shown in FIG. 5 , in the control-plane, there may be a ProSe Sidelink(PC5) interface (e.g., a sidelink interface) between the remote UE andthe relay UE, a Uu interface between the relay UE and a radio accessnetwork (RAN) (also referred to herein as a 5G access network (5G-AN) ora next generation RAN (NG-RAN)), and an N2 interface between the RAN anda core network (e.g., a 5G core network (5GC)). The 5GC may include anaccess and mobility management function (AMF), a session managementfunction (SMF), and/or a user-plane function (UPF).

The remote UE and the relay UE may be associated with respective PC5protocol stacks enabling communication on the PC5 interface between theremote UE and the relay UE. The PC5 protocol stack may include a PC5radio link control (RLC) component, a PC5 medium access control (MAC)component, a PC5 physical (PHY) component, and/or the like. “PC5” isgenerally referred to herein as “sidelink” (e.g., sidelink signalinginterfaces, sidelink unicast link, sidelink RLC channels, and/or thelike). Communications between the remote UE and the relay UE using thePC5 interface may be referred to as sidelink communications. In someaspects, the respective PC5 protocol stacks may be associated with oneor more of PC5-signaling (PC5-S) entities, PC5-radio resource control(RRC) entities, or PC5-PDCP entities. The PC5-S entity may manage asidelink signaling interface, such as a PC5-S interface. A UE thatincludes a PC5-S entity and/or a PC5-RRC entity may handle controlsignaling and configuration of a sidelink connection with another UE,such as the connection used for relaying between the remote UE and therelay UE. In some aspects, the PC5 protocol stacks may not include PC5-Sentities or PC5-RRC entities. Also, in some cases, the RAN may handlecontrol signaling and configuration of the sidelink connection.

As shown in FIG. 5 , the remote UE is associated with a non-accessstratum (NAS) stack, which may include an NAS session management(NAS-SM) component, and one or more radio access components (e.g., aUu-RRC component and a Uu-PDCP component). The Uu-RRC component may bereferred to herein as an NR-RRC component. Similarly, the Uu-PDCPcomponent may be referred to as an NR-PDCP component.

The relay UE may be associated with a radio access stack, including aUu-RLC component (e.g., an NR-RLC component), a Uu-MAC component (e.g.,an NR-MAC component), and a Uu-PHY component (e.g., an NR-PHYcomponent). Furthermore, the RAN is associated with a radio accessinterface stack, which may include a Uu-RRC entity, a Uu-PDCP entity, aUu-RLC component, a Uu-MAC component, and a Uu-PHY component.

As shown by the lines in FIG. 5 , control-plane traffic may betransported between the Uu-RRC components and the Uu-PDCP component ofthe remote UE and the RAN. Such control-plane traffic may be transportedvia one or more bearers, such as a signaling radio bearer (SRB). An SRBcan also be referred to as a radio bearer, a radio access bearer, and/oran end-to-end bearer. Control-plane traffic may be transported betweenthe PC5 protocol stacks of the remote UE and the relay UE via one ormore RLC channels. Similarly, control-plane traffic may be transportedbetween the radio access stack of the relay UE and the RAN via one ormore RLC channels (e.g., using the Uu interface).

As shown in control-plane protocol architecture 500 and 505, the relayUE and the RAN may include a radio access adaptation layer entity (e.g.,a Uu adaptation layer entity and/or an NR adaptation layer entity). Theadaptation layer entity of the relay UE may handle relaying from theremote UE to the network or from the network to the remote UE. As usedherein, “the network” may refer to any one or more of the RAN, the AMF,the SMF, the UPF, or the 5GC. The adaptation layer may be referred toherein as an adaptation layer entity. In some aspects, the adaptationlayer entity may be a separate entity between an RLC entity and a packetdata convergence entity. In some aspects, the adaptation layer entitymay be logically part of the packet data convergence entity or the RLCentity.

As shown in control-plane protocol architecture 500, a sidelinkinterface adaptation layer entity (e.g., a PC5 adaptation layer entityor a sidelink adaptation layer entity) may not be supported at the relayUE and the remote UE. Therefore, in some aspects, the relay UE and theremote UE may not include a PC5 adaptation layer entity. As shown incontrol-plane protocol architecture 505, a sidelink interface adaptationlayer entity (e.g., a PC5 adaptation layer entity or a sidelinkadaptation layer entity) may be supported at the relay UE and the remoteUE. Therefore, in some aspects, the relay UE and the remote UE mayinclude a PC5 adaptation layer entity.

The stacks of the remote UE and/or the RAN may communicate with oneanother. For example, a message (e.g., an NR RRC message generated bythe radio access protocol stack) may be communicated between the radioaccess stack of the remote UE and the PC5 stack of the remote UE (e.g.,between the Uu-PDCP entity and/or the PC5-RLC entity or thePC5-adaptation layer entity).

As indicated above, FIG. 5 is provided as an example. Other examples maydiffer from what is described with respect to FIG. 5 .

FIG. 6 is a diagram illustrating examples of user-plane protocolarchitecture 600 and 605 for a UE-to-network relay. As shown in FIG. 5 ,the user-plane protocol architecture 600 and 605 may correspond to aremote UE (e.g., UE 120) and a relay UE (e.g., UE 120).

As shown in FIG. 6 , the user-plane protocol architecture 600 and 605may include similar entities to the entities described above inconnection with FIG. 5 . For example, the remote UE may include a PC5protocol stack (e.g., including a PC5-RLC component, a PC5-MAC componentand a PC5-PHY component). The PC5 protocol stack of the remote UE maynot include an adaptation layer entity as shown in user-plane protocolarchitecture 600. In some aspects, the PC5 protocol stack of the remoteUE may include an adaptation layer entity as shown in user-planeprotocol architecture 605.

The relay UE may include a PC5 protocol stack (e.g., including a PC5-RLCcomponent, a PC5-MAC component and a PC5-PHY component). The PC5protocol stack of the relay UE may not include an adaptation layerentity, as shown in user-plane protocol architecture 600. In someaspects, the PC5 protocol stack of the relay UE may include anadaptation layer entity, as shown in user-plane protocol architecture605. The relay UE may include a radio access stack (e.g., including anadaptation layer entity, a Uu-RLC component, a Uu-MAC component, and aUu-PHY component). Similarly, the RAN may include a radio access stack.

As shown in FIG. 6 , the remote UE may be associated with a user-planeprotocol stack, which may include an Internet protocol (IP) component,an application (APP) component (not shown in FIG. 6 ), a service dataadaptation protocol (SDAP) component (e.g., a Uu SDAP component or an NRSDAP component), and/or a PDCP component (e.g., a Uu PDCP component oran NR PDCP component). The RAN may include a service data adaptationprotocol (SDAP) component (e.g., a Uu SDAP component or an NR SDAPcomponent), and a PDCP component (e.g., a Uu PDCP component or an NRPDCP component). As shown in FIG. 6 , the RAN and the 5GC may include anN3 stack (e.g., which may include a UPF). The RAN and the 5GC maycommunicate via a general packet radio service (GPRS) tunneling protocol(GTP) for user data (collectively, a GTP-U) tunnel. The 5GC may includean IP component which may communicate with the IP component of theremote UE.

As shown by the lines in FIG. 6 , user-plane traffic may be transportedbetween the Uu-SDAP components and the Uu-PDCP component of the remoteUE and the RAN. Such user-plane traffic may be transported via one ormore bearers, such as a data radio bearer (DRB). Similar to an SRB forcontrol-plane traffic, a DRB can also be referred to as a radio bearer,a radio access bearer, and/or an end-to-end bearer. User-plane trafficmay be transported between the PC5 protocol stacks of the remote UE andthe relay UE via one or more RLC channels. Similarly, user-plane trafficmay be transported between the radio access stack of the relay UE andthe RAN via one or more RLC channels (e.g., using the Uu interface).

The adaptation layer may handle the mapping of these types of flows,channels, and bearers to each other to facilitate relay services, asdescribed elsewhere herein. The adaptation layer may be referred toherein as a relay adaptation layer. A radio access bearer may include anSRB and/or a DRB, among other examples. An RLC channel can also bereferred to as an RLC bearer. In such a case, an RLC channel identifierassociated with the RLC channel may be referred to as an RLC beareridentifier.

As indicated above, FIG. 6 is provided as an example. Other examples maydiffer from what is described with respect to FIG. 6 .

A UE (referred to herein as a relay user equipment or relay UE) mayrelay communications from another UE (referred to herein as a remoteuser equipment or remote UE) to a network or from the network to theremote UE. In some aspects, the relay UE may perform Layer 2UE-to-network relaying, in which an adaptation layer (e.g., a Uuadaptation layer) in the Layer 2 stack of the relay UE performsforwarding of the remote UE's communications, as compared to Layer 3relaying which may occur in the IP layer. Communications between therelay UE and the remote UE may be referred to herein as sidelinkcommunications. In some Layer 2 UE-to-network relaying applications, NASand RRC messages may be transparently transferred between the remote UEand the network using PDCP end-to-end connections (e.g., using adedicated end-to-end SRB or DRB).

The PC5 interface may provide a sidelink interface between UEs. Forexample, Vehicle-to-Anything (V2X) communications in accordance with NRRelease 16 may be performed using a PC5 unicast control-plane stack,which may include a PC5-S interface and a PC5 access-stratum (AS)(PC5-AS) interface, such as a PC5-RRC interface. UEs communicating usingthe PC5 interface may configure a sidelink unicast link context andexchange AS information using the PC5-S interface and the PC5-RRCinterface. The UEs may be associated with a PC5 user-plane stack, whichmay include, for example, a PC5-SDAP entity and/or a PC5-PDCP entity.

Traffic flows may be associated with various quality of service (QoS)requirements, relay services, and security settings. Furthermore, arelay UE may provide a Layer 2 relay service for one or more remote UEs,which may be associated with respective traffic flows, RLC channels,bearers, and so on. Therefore, challenges may arise in the relaying ofcommunications between one or more remote UEs and the network, such ashow to handle traffic with varying QoS requirements, how to map radioaccess RLC channels to sidelink RLC channels, how to handle radio accessbearers such as signaling radio bearers and data radio bearers, how tohandle relaying for multiple remote UEs, and so on, which may complicatethe Layer 2 relay service.

As described above, a relay UE may use the Uu adaptation layer forsupporting downlink bearer mapping and data multiplexing betweenmultiple end-to-end radio bearers (e.g., SRBs and/or DRBs) of a remoteUE (and/or multiple remote UEs) and a single Uu RLC channel over therelay UE Uu path. For example, identity information of a remote UE Uuradio bearer (e.g., an SRB or a DRB) may be included in the Uuadaptation layer in uplink scenarios to enable the RAN (e.g., a networkentity of the RAN, such as a base station) to correlate the packetsreceived from the relay UE to the correct end-to-end radio bearer of theremote UE. Additionally, identity information of a remote UE may beincluded in the Uu adaptation layer in uplink scenarios to enable theRAN (e.g., a base station) to correlate the packets received from therelay UE to the correct remote UE. Similarly, the identity informationof a remote UE Uu radio bearer (e.g., an SRB or a DRB) may be includedin the Uu adaptation layer in downlink scenarios (e.g., by a networkentity of the RAN) to enable the relay UE to correlate or map thereceive packets to a correct PC5 RLC channel between the relay UE andthe remote UE that is associated with the remote UE Uu radio bearer.Additionally, the identity information of a remote UE may be included inthe Uu adaptation layer in downlink scenarios (e.g., by a network entityof the RAN) to enable the relay UE to correlate or map the receivepackets to a correct remote UE.

However, as described above, the relay UE and the remote UE may includea PC5 adaptation layer in some cases. Therefore, functions of the PC5adaptation layer are and/or how the functions of PC5 adaptation layereffect or integrate with the functions of the Uu PC5 adaptation layerneed to be clarified or defined. Moreover, the identity informationincluded in the adaptation layer (e.g., the PC5 adaptation layer and/orthe Uu adaptation layer) may not be protected as it is not included in adedicated end-to-end radio bearer (e.g., an SRB or a DRB). Therefore,this identify information needs to be protected to ensure that theidentify information cannot be obtained to identify or locate the remoteUE (e.g., to satisfy security requirements of the remote UE or asidelink communication network, such as a V2X network).

Some techniques and apparatuses described herein enable a configurationof a sidelink interface (e.g., PC5) adaptation layer. The PC5 adaptationlayer may support data transfer, bearer mapping, and data routingassociated with a Layer 2 relay service. For example, a remote UE may beassociated with multiple radio bearers which may be multiplexed to asingle PC5 RLC channel. The remote UE may include a remote UE beareridentifier (e.g., identifying the radio bearer associated with thetraffic) in the PC5 adaptation layer. Therefore, the relay UE may beenabled to identify the remote UE bearer identifier and map the trafficto a correct Uu RLC channel to be transmitted to a network entity. Thenetwork entity may be enabled to identify the radio bearer associatedwith the traffic and pass the traffic to the correct radio bearer in anupper layer.

Some techniques and apparatuses described herein provide signaling forconfiguration of the adaptation layer (e.g., the PC5 adaptation layerand/or the Uu adaptation layer), configuration of radio bearer mappings,privacy and security support, and traffic routing. As a result, a Layer2 relay service is configured to handle QoS requirements, one or moreremote UEs, various service coverage and connection states, and mappingsof radio bearers, RLC channels, and so on. In this way, efficiency ofLayer 2 relaying is improved and conformance with QoS requirementsand/or security requirements is improved.

FIG. 7 is a diagram illustrating an example 700 of configuring asidelink interface (e.g., PC5) adaptation layer for a relay service, inaccordance with various aspects of the present disclosure. As shown,example 700 includes a remote UE 705, a relay UE 710, and a networkentity 715. The network entity 715 may be a base station (e.g., basestation 110), a gNB, and/or an NG-RAN, among other examples.

As shown by reference number 720, the relay UE 710 and the remote UE 705may establish a sidelink unicast link via a sidelink signaling interface(e.g., a PC5-S interface). In some aspects, the sidelink unicast linkmay be associated with an identifier. For example, the sidelink unicastlink may be identified by a combination of a source Layer 2 identifierand a destination Layer 2 identifier. One of the source Layer 2identifier and the destination Layer 2 identifier may identify theremote UE 120, and the other may identify the relay UE 120. Theidentifier may be used to route traffic via the Layer 2 relay, asdescribed elsewhere herein. The identifier may be referred to herein asa unique index.

A sidelink unicast link for a particular relay service may be configuredwith a corresponding security setting that is associated with theparticular relay service and/or relay service code. In some aspects,sidelink control plane (e.g., PC5-CP) signaling may use thecorresponding security setting for control-plane signaling specific tothe particular relay service. In some aspects, all services associatedwith the relay service code (e.g., data radio bearers (DRBs) and/orsignaling radio bearers (SRBs)) may use the same sidelink security.

In some aspects, the sidelink unicast link may support multiple sidelinkRLC channels (e.g., N sidelink RLC channels, where Nis an integer) forradio access SRBs and/or DRBs. In some aspects, the sidelink unicastlink may support multiple radio access protocol data unit (PDU) sessionson a single link. In some aspects, the sidelink unicast link may supportmultiple sidelink RLC channels configured with the same QoS.

As described above, the remote UE 705 and the relay UE 710 may include aPC5 adaptation layer entity. The remote UE 705, the relay UE 710, andthe network entity 715 may obtain (e.g., assign, transmit, and/orreceive) configuration information for the PC5 adaptation layer. Theconfiguration information may support the relaying of remote UE 120'straffic. The configuration information may include a remote UEidentifier for the remote UE identifying the sidelink unicast linkbetween the remote UE 705 and the relay UE 710 for a relay service(e.g., a RemoteUEIndex). The configuration information may includebearer identifier information identifying one or more remote UE bearers(e.g., SRBs and/or DRBs) between the remote UE 705 and the networkentity 715 associated with the relay service. The bearer identifierinformation may identify, for a radio bearer of the remote UE, a remotebearer identifier (e.g., a RemoteUEBearerID) identifying the remote UEbearer (e.g., the Uu bearer) for relaying purposes.

The configuration information may include RLC channel mappinginformation that includes a mapping between a bearer identifier and oneor more RLC channels of the sidelink unicast link (e.g., PC5 RLCchannels) and one or more RLC channels of a link with the network entity715 (e.g., Uu RLC channels). For example, the configuration informationmay include a configuration for one or more RLC channels. Suchconfiguration information may include RLC channel identifierinformation, such as an information element that identifies RLC channelidentifiers of a set of RLC channels (e.g., sidelink RLC channels and/orradio access RLC channels) associated with the relay service.Additionally, or alternatively, such information may include a set ofparameters to configure corresponding RLC and MAC entities for an RLCchannel. The RLC channel mapping information may map a remote UE beareridentifier to at least on PC5 RLC channel identifier and/or at least oneUu RLC channel identifier.

A radio access link between the relay UE 710 and network entity 715 maybe referred to as a link with the network entity 715. The sidelinkunicast link and the radio access link may be collectively referred toas a relaying connection.

In some aspects, the relay UE 710 may configure unicast links withmultiple remote UEs 705 (e.g., M remote UEs 705, where M is an integer).In some aspects, the relay UE 710 may support multiple radio access RLCchannels for relaying traffic to the multiple remote UEs 705. In someaspects, a single radio access RLC channel may be mapped to multiplesidelink RLC channels with the same QoS level. In some aspects, a singleradio access RLC channel may be mapped to multiple sidelink RLC channelswith different QoS levels. In this case, in some aspects, the radioaccess RLC channel may be assigned a highest QoS level of the differentQoS levels. In other aspects, scheduling by the network entity 715 andlink control protocol (LCP) operations at the relay UE 710 may considereach of the QoS levels associated with the multiple sidelink RLCchannels when scheduling and relaying communications.

As shown by reference number 725, in some aspects, the relay UE 710 mayassign a remote UE identifier for each remote UE 705 in communicationwith the relay UE 710. The remote UE identifier may be referred toherein as a remote UE index. As described above, the remote UEidentifier may be a unique index identifying the sidelink unicast linkbetween the remote UE 705 and the relay UE 710. In some aspects, therelay UE 710 may assign the remote UE identifier during the setup of thesidelink unicast link between the remote UE 705 and the relay UE 710(e.g., as described above in connection with reference number 720). Forexample, as shown by reference number 730, the relay UE 710 maytransmit, to the remote UE 705, an indication of the remote UEidentifier during the sidelink unicast link setup. The relay UE 710 maytransmit, to the remote UE 705, the indication of the remote UEidentifier in an RRC message, such as a direct security mode commandmessage or a direct communication accept message.

As shown by reference number 735, if the relay UE 710 assigns the remoteUE identifier, then the relay UE 710 may indicate the remote UEidentifier to the network entity 715. For example, the relay UE 710 maytransmit, to the network entity 715, an indication of the remote UEidentifier for the remote UE 705 (and/or remote UE identifier(s) for oneor more other remote UEs 705 in communication with the relay UE 710) viaan RRC message. The RRC message may be an NR RRC message, such as asidelink UE information message (e.g., sidelinkUEInformationNR).

As shown by reference number 740, in some aspects, the network entity715 may assign a remote UE identifier for the remote UE 705 (and/or oneor more other remote UEs 705). For example, in an initial setup of therelay service between the remote UE 705, the relay UE 710, and thenetwork entity 715, the remote UE 705 may transmit, to the networkentity 715, an RRC setup request to establish the relay service. Thenetwork entity 715 may assign the remote UE identifier for the remote UE705 when establishing, configuring, and/or setting up the relay service.In some aspects, the remote UE identifier assigned by the network entity715 may be a cell radio network temporary identifier (C-RNTI) thatidentifies the sidelink unicast link between the remote UE 705 and therelay UE 710.

In some aspects, the remote UE identifier assigned by the network entity715 may be a unique UE identifier or a temporary UE identifier that isassigned for each remote UE 705 in communication with the relay UE 710.In that case, the network entity 715 may assign and/or configure theremote UE identifiers on a per-relay UE basis. This means that theremote UE identifier may be unique among the remote UEs 705 incommunication with the relay UE 710. In other words, rather than theremote UE identifier being unique among every UE 705, the remote UEidentifier may only be required to be unique among the remote UEs 705 incommunication with the relay UE 710. For example, if there are 5 remoteUEs 705 in communication with the relay UE 710, then the remote UEidentifiers may only be required to be unique among the 5 remote UEs705. This may enable the remote UE identifier to be a shorteridentifier, thereby reducing a payload size when communicating using theremote UE identifier (e.g., when the remote UE identifier in included inan adaptation layer header as described in more detail below).

As shown by reference number 745, the network entity 715 may transmit anindication of the remote UE identifier to the remote UE 705 via an RRCmessage (e.g., an NR RRC message). For example, the RRC message may bean RRC setup message, an RRC resume message, an RRC reestablishmentmessage, and/or an RRC reconfiguration message, among other examples.

As shown by reference number 750, the network entity 715 may transmit anindication of the remote UE identifier to the relay UE 705. For example,the network entity 715 may transmit, to the relay UE 710, an RRC messageindicating the remote UE identifier to the relay UE 705. In someaspects, the network entity may indicate the remote UE identifier to therelay UE 705 as part of a relaying configuration for the relay UE 710.For example, the network entity 715 may configure the relay servicebetween the remote UE 705 and the network entity 715 and indicate an RLCchannel configuration, RLC channel mapping information, bearer mappinginformation, and/or data routing information, among other examples. Thenetwork entity 715 may include the remote UE identifier in a field ofthe relaying configuration (e.g., in a RemoteUEIndex field of therelaying configuration). In this way, the network entity 715 mayindicate the remote UE identifier of the remote UE 705 to the relay UE710 and indicate that the relaying configuration is for that particularremote UE 705 (e.g., identified based at least in part on the remote UEidentifier).

As shown by reference number 755, the network entity 715 may determinebearer identifier information for one or more remote UE bearers (e.g.,DRBs and/or SRBs) between the remote UE 705 and a network entity 715.The one or more remote UE bearers may be end-to-end radio bearersbetween the remote UE 705 and the network entity 715. The beareridentifier information may include, for each remote UE bearer, a remoteUE bearer identifier (e.g., a RemoteUEBearerID) for the bearer that isto be used for relaying purposes. The remote UE bearer identifier may beassociated with a remote UE Uu bearer (e.g., a DRB and/or an SRB).

In some aspects, the remote UE bearer identifier may be the same as anidentifier of the radio bearer. For example, for an SRB of the remoteUE, the remote UE bearer identifier may be the SRB identifier of theSRB. Similarly, for a DRB of the remote UE, the remote UE beareridentifier may be the DRB identifier of the DRB. In some aspects, theremote UE bearer identifier may be a unique identifier configured by thenetwork entity for the radio bearer that is to be used when the relayconnection (or relay path) is used in addition to the radio bearer. Inthis way, if the remote UE bearer identifier is updated (e.g., asdescribed in more detail below in connection with FIG. 13 ), the remoteUE 705 may not be required to release and reconfigure the radio bearer.For example, when the radio bearer identifier (e.g., the SRB identifieror the DRB identifier) is updated, the remote UE 705 may be required torelease and reconfigure the radio bearer. By using a different uniqueidentifier as the remote UE bearer identifier, the remote UE 705 mayavoid releasing and reconfiguring the radio bearer when the remote UEbearer identifier for the radio bearer is updated or changed.

The network entity 705 may determine mapping information for the remoteUE bearer identifier(s). The mapping information may be referred toherein as RLC channel mapping information and/or bearer identifiermapping information. The mapping information may map a remote UE beareridentifier to one or more PC5 RLC channels and/or one or more Uu RLCchannels. For example, in a relaying configuration, there may be amapping between a radio bearer (e.g., a DRB or SRB) and one or more RLCchannels, radio access RLC channels, and/or remote UEs. For example, themapping may be provided via a pre-configured relaying SRB configuration.As another example, the mapping may be provided by the network entitybased at least in part on the relay UE 710 indicating support for therelay service. In this case, the relay UE 710 may transmit informationindicating support for the relay service. As still another example, thenetwork entity 715 may provide a mapping for a DRB based at least inpart on a request from the relay UE 710 or based at least in part on ahandover of the remote UE 705 to the sidelink unicast link (e.g., from aradio access link to the sidelink unicast link).

By using the remote UE bearer identifier, the relay UE 710 is enabled toidentify a correct RLC channel for data routing based at least in parton the remote UE bearer identifier. As a result, the receiving device(e.g., the remote UE 705 and/or the network entity 715) may receive asignal on the correct RLC channel and may identify a radio bearer (e.g.,a DRB or an SRB) associated with the signal (e.g., based at least inpart on the remote UE bearer identifier). Therefore, the remote UE 705and the network entity 715 may use a remote UE bearer identifier toroute traffic to the appropriate bearers and/or RLC channels.

As shown by reference number 760, the network entity 715 may transmit,to the relay UE 710, an indication of the bearer identifier information(e.g., one or more remote UE bearer identifiers and mapping informationfor the remote UE bearer identifiers). The network entity 715 maytransmit the bearer identifier information to the relay UE 710 via anRRC message. For example, the network entity 715 may transmit the beareridentifier information to the relay UE 710 as part of the relayconfiguration. The relay UE 710 may maintain the mapping of remote UEbearer identifiers to PC5 RLC channels and Uu RLC channels.

As shown by reference number 765, the network entity 715 may transmit,to the remote UE 705, an indication of the bearer identifierinformation. The network entity 715 may transmit the bearer identifierinformation to the remote UE 705 via an RRC message. For example, thenetwork entity 715 may transmit the bearer identifier information to theremote UE 705 in one or more RRC reconfiguration messages. For example,the network entity 715 may transmit the bearer identifier information tothe remote UE 705 as part of a bearer configuration for thecorresponding DRBs and SRBs. A remote UE bearer identifier may beincluded in a field of an RRC message, such as a RemoteUEBearerID field,that configures the radio bearer associated with the remote UE beareridentifier.

The remote UE 705 may maintain a mapping of radio bearer identifier(e.g., SRB identifier or DRB identifier) to remote UE bearer identifierto enable the remote UE 705 to use the PC5 adaptation layer (e.g., byincluding the remote UE bearer identifier in a PC5 adaptation layerheader or by identifying the remote UE bearer identifier in a PC5adaptation layer header received from the relay UE 710) to route trafficto the appropriate radio bearer at the network entity 715 (e.g., in theuplink) and/or at the remote UE 705 (e.g., in the downlink). Similarly,the network entity 715 may maintain a mapping of radio bearer identifier(e.g., SRB identifier or DRB identifier) to remote UE bearer identifierto enable the network entity 715 to use the Uu adaptation layer (e.g.,by including the remote UE bearer identifier in a Uu adaptation layerheader or by identifying the remote UE bearer identifier in a Uuadaptation layer header received from the relay UE 710) to route trafficto the appropriate radio bearer at the network entity 715 (e.g., in theuplink) and/or at the remote UE 705 (e.g., in the downlink).

In some aspects, the remote UE 705 may be configured with a defaultremote UE bearer identifier associated with an SRB that is to be usedfor RRC messages using a common control channel. For example, one ormore access stratum SRBs, such as SRB0 (which may be for RRC messagesusing a common control channel), SRB1 (which may be for RRC messages andNAS messages prior to establishment of SRB2), SRB2 (which may be for RRCmessages that include logged measurement information as well as NASmessages after security activation), and/or SRB3 (which may be for RRCmessages in dual connectivity such as over radio access and sidelinklinks) may be set up for an NR connection. However, prior to a relayconnection being established, the remote UE 705 may be unaware of theremote UE identifiers for the different SRBs, for example, and the oneor more SRBs may not be configured. Therefore, the remote UE 705 maytransmit an RRC setup request message to the network entity 715 via therelay UE 710 to establish the relay connection. The remote UE 705 maytransmit the RRC setup request message using the SRB that is to be usedfor RRC messages using a common control channel (e.g., SRB0). As theremote UE 705 may not be aware of, or may not be configured with, thebearer identifier information at this time, the remote UE 705 may usethe default remote UE bearer identifier to route the traffic to the SRBthat is to be used for RRC messages using a common control channel(e.g., SRB0). The default remote UE bearer identifier may bepre-configured at the remote UE 705 and/or may be a reserved remote UEbearer identifier for RRC messages transmitted over SRB0. The relay UE710 may be configured (or pre-configured) with the default remote UEbearer identifier in a similar manner to enable the relay UE 710 toroute traffic to the appropriate RLC channels when receiving trafficthat uses the default remote UE bearer identifier (e.g., in a PC5adaptation layer header).

The remote UE 705, the relay UE 710, and/or the network entity 715 mayuse the configuration of the identifiers and corresponding mappinginformation described above to communicate using an adaptation layer, asdescribed in more detail below in connection with FIG. 9 (depicting anuplink scenario) and/or FIG. 10 (depicting a downlink scenario).

For example, the remote UE 705 may use the identifiers and correspondingmapping information to generate a PC5 adaptation layer header to routetraffic to the appropriate radio bearers and/or RLC channels at therelay UE 710 and the network entity 715. Similarly, the remote UE 705may use the identifiers and corresponding mapping information to routetraffic to the appropriate radio bearers at an upper layer based atleast in part on a PC5 adaptation layer header received from the relayUE 710. The relay UE 710 may use the identifiers and correspondingmapping information to generate a PC5 adaptation layer header from a Uuadaptation layer header received from the network entity 715 and toroute traffic to the correct PC5 RLC channel. Similarly, the relay UE710 may use the identifiers and corresponding mapping information togenerate a Uu adaptation layer header from a PC5 adaptation layer headerreceived from the remote UE 705 and to route traffic to the correct UuRLC channel. The network entity 715 may use the identifiers andcorresponding mapping information to generate a Uu adaptation layerheader to route traffic to the appropriate radio bearers and/or RLCchannels at the relay UE 710 and the remote UE 705. Similarly, thenetwork entity 715 may use the identifiers and corresponding mappinginformation to route traffic to the appropriate radio bearers at anupper layer based at least in part on a Uu adaptation layer headerreceived from the relay UE 710.

In some aspects, the remote UE 705, the relay UE 710, and/or the networkentity 715 may perform one or more privacy update procedures to updatethe identifiers described above (e.g., the remote UE identifier and/orthe remote UE bearer identifier). The one or more privacy updateprocedures are described in more detail below in connection with FIGS.11, 12, and 13 .

As indicated above, FIG. 7 is provided as an example. Other examples maydiffer from what is described with respect to FIG. 7 .

FIG. 8 is a diagram illustrating an example 800 of a sidelink interface(e.g., PC5) adaptation layer header, in accordance with various aspectsof the present disclosure. The PC5 adaptation layer header (e.g., one ormore fields of the PC5 adaptation layer header) may provide support fordata routing and mapping of RLC channels to bearers associated with theremote UE (e.g., remote UE 705).

For example, the PC5 adaptation layer header may include a first field810 that identifies an identifier associated with the remote UE (e.g., aremote UE identifier or a remote UE index), which may be a unique indexidentifying the remote UE's unicast link with the relay UE. In someaspects, the unique index may include the sidelink unicast linkidentifier described in connection with FIG. 7 . As another example, thePC5 adaptation layer header may include a second field 820 thatidentifies a remote UE bearer identifier corresponding to a radio accessbearer of the remote UE. As yet another example, the PC5 adaptationlayer header may include a third field 830 that indicates a route overwhich the communication is to be relayed. For a single-hop relay or asingle-relay connection, the third field 830 may not be present or maybe set to a value indicating a single-hop relay or a single-relayconnection (e.g., 1). As shown, the PC5 adaptation layer header may beappended by the remote UE to an NR-PDCP PDU generated by the remote UE120. A similar (or the same) header (e.g., a Uu adaptation layer header)may be appended by a network entity to an NR-PDCP PDU generated for theremote UE 120 that includes one or more (or all) of the fields of thePC5 adaptation layer header.

As indicated above, FIG. 8 is provided as an example. Other examples maydiffer from what is described with respect to FIG. 8 .

FIG. 9 is a diagram illustrating an example 900 of uplink relaysignaling, in accordance with various aspects of the present disclosure.As shown, example 900 includes a remote UE 905, a relay UE 910, and anetwork entity 915. The network entity 915 may be a base station (e.g.,base station 110), a gNB, and/or an NG-RAN, among other examples. Asshown by reference number 920, the remote UE 905, the relay UE 910,and/or the network entity 915 may perform a relay connection setup(e.g., a sidelink layer 2 relay connection setup). The relay connectionsetup may be similar to, or the same as, example 700 described above inconnection with FIG. 7 . For example, the relay connection setup mayinclude one or more (or all) of the steps described above in connectionwith FIG. 7 .

As shown by reference number 925, the remote UE 905 may obtain oridentify traffic that is to be transmitted to the network entity 915 viathe relay UE 910. For example, the remote UE 905 may receive, from anupper layer, a PDCP PDU to be relayed to the network entity 915 via therelay UE 910. The remote UE 905 may identify a radio access (e.g., Uu)radio bearer (e.g., an SRB identifier or a DRB identifier) associatedwith the PDCP PDU. The remote UE 905 may identify a remote UE beareridentifier associated with the radio access radio bearer (e.g., based atleast in part on the mapping information for the remote UE beareridentifier described above). The remote UE 905 may identify a remote UEidentifier (e.g., a remote UE index) associated with the remote UE 905.The remote UE 905 may generate a PC5 adaptation layer header based atleast in part on the remote UE bearer identifier and the remote UEidentifier. For example, the PC5 adaptation layer header may be similarto (or the same as) the PC5 adaptation layer header described above inconnection with FIG. 8 . The remote UE 905 may append the PC5 adaptationlayer header to the PDCP PDU. The remote UE 905 may transfer the PDCPPDU (with the PC5 adaptation layer header) to lower layer(s) fortransmission to the relay UE 910 over the appropriate PC5 RLC channel. APDCP PDU with an adaptation layer header may be referred to herein as anadaptation layer PDU.

As shown by reference number 930, the relay UE 910 may receive the PDCPPDU (with the PC5 adaptation layer header) from the remote UE 905 viathe PC5 RLC channel. The relay UE 910 may identify the remote UE beareridentifier and/or the remote UE identifier (e.g., remote UE index) basedat least in part on the PC5 adaptation layer header. The relay UE 910may generate a Uu adaptation layer header based at least in part on thePC5 adaptation layer header. For example, the relay UE 910 may use thefields in the PC5 adaptation layer header (e.g., without modification)to generate corresponding fields in the Uu adaptation layer header. Insome aspects, the relay UE 910 may remove the PC5 adaptation layerheader from the PDCP PDU and append the Uu adaptation layer header tothe PDCP PDU.

As shown by reference number 935, the relay UE 910 may identify anappropriate Uu RLC channel to transmit the PDCP PDU (e.g., with the Uuadaptation layer header) on. For example, the relay UE 910 may use thebearer identifier information (e.g., the mapping of remote UE beareridentifiers to PC5 RLC channels and Uu RLC channels) to identify a UuRLC channel associated with the remote UE bearer identifier that wasincluded in the PC5 adaptation layer header. As shown by referencenumber 940, the relay UE 910 may transmit, to the network entity 915,the PDCP PDU (e.g., with the Uu adaptation layer header) on theappropriate Uu RLC channel.

As shown by reference number 945, the network entity 915 may receive thePDCP PDU (e.g., with the Uu adaptation layer header) on the appropriateUu RLC channel. The network entity 915 may identify the remote UE beareridentifier and/or the remote UE identifier (e.g., remote UE index) basedat least in part on the Uu adaptation layer header. The network entity915 may identify a radio access radio bearer (e.g., an SRB and/or a DRB)associated with the remote UE bearer identifier (e.g., based at least inpart on the mapping information for the remote UE bearer identifierdescribed above). The network entity 915 may remove the Uu adaptationlayer header from the PDCP PDU. The network entity 915 may transfer thePDCP PDU (e.g., an NR PDCP PDU) to an upper layer based at least in parton the identified radio access radio bearer associated with the PDCPPDU. As a result, an end-to-end relay connection can be formed thatenables the remote UE 905 to transfer traffic to the network entity 915via the appropriate end-to-end radio bearer via the relay UE 910.

As indicated above, FIG. 9 is provided as an example. Other examples maydiffer from what is described with respect to FIG. 9 .

FIG. 10 is a diagram illustrating an example 1000 of downlink relaysignaling, in accordance with various aspects of the present disclosure.As shown, example 1000 includes a remote UE 1005, a relay UE 1010, and anetwork entity 1015. The network entity 1015 may be a base station(e.g., base station 110), a gNB, and/or an NG-RAN, among other examples.As shown by reference number 1020, the remote UE 1005, the relay UE1010, and/or the network entity 1015 may perform a relay connectionsetup (e.g., a sidelink layer 2 relay connection setup). The relayconnection setup may be similar to, or the same as, example 700described above in connection with FIG. 7 .

As shown by reference number 1025, the network entity 1015 may obtain oridentify traffic that is to be transmitted to the remote UE 1005 via therelay UE 1010. For example, the network entity 1015 may receive, from anupper layer, a PDCP PDU to be relayed to the remote UE 1005 via therelay UE 1010. The network entity 1015 may identify a radio access(e.g., Uu) radio bearer (e.g., an SRB identifier or a DRB identifier)associated with the PDCP PDU. The network entity 1015 may identify aremote UE bearer identifier associated with the radio access radiobearer (e.g., based at least in part on the mapping information for theremote UE bearer identifier described above). The network entity 1015may identify a remote UE identifier (e.g., a remote UE index) associatedwith the remote UE 1005. The network entity 1015 may generate a Uuadaptation layer header based at least in part on the remote UE beareridentifier and the remote UE identifier. The network entity 1015 mayappend the Uu adaptation layer header to the PDCP PDU. The networkentity 1015 may transfer the PDCP PDU (with the Uu adaptation layerheader) to lower layer(s) for transmission to the relay UE 1010 over theappropriate Uu RLC channel.

As shown by reference number 1030, the relay UE 1010 may receive thePDCP PDU (with the Uu adaptation layer header) from the network entity1015 via the Uu RLC channel. The relay UE 1010 may identify the remoteUE bearer identifier and/or the remote UE identifier (e.g., remote UEindex) based at least in part on the Uu adaptation layer header. Therelay UE 1010 may generate a PC5 adaptation layer header based at leastin part on the Uu adaptation layer header. For example, the relay UE1010 may use the fields in the Uu adaptation layer header (e.g., withoutmodification) to generate corresponding fields in the PC5 adaptationlayer header. In some aspects, the relay UE 1010 may remove the Uuadaptation layer header from the PDCP PDU and append the PC5 adaptationlayer header to the PDCP PDU.

As shown by reference number 1035, the relay UE 1010 may identify anappropriate PC5 RLC channel to transmit the PDCP PDU (e.g., with the PC5adaptation layer header) on. For example, the relay UE 1010 may use thebearer identifier information (e.g., the mapping of remote UE beareridentifiers to PC5 RLC channels and Uu RLC channels) to identify a PC5RLC channel associated with the remote UE bearer identifier that wasincluded in the Uu adaptation layer header. As shown by reference number1040, the relay UE 1010 may transmit, to the remote UE 1005, the PDCPPDU (e.g., with the PC5 adaptation layer header) on the appropriate PC5RLC channel.

As shown by reference number 1045, the remote UE 1005 may receive thePDCP PDU (e.g., with the PC5 adaptation layer header) on the appropriatePC5 RLC channel. The remote UE 1005 may identify the remote UE beareridentifier and/or the remote UE identifier (e.g., remote UE index) basedat least in part on the PC5 adaptation layer header. The remote UE 1005may identify a radio access radio bearer (e.g., an SRB and/or a DRB)associated with the remote UE bearer identifier (e.g., based at least inpart on the mapping information for the remote UE bearer identifierdescribed above). The remote UE 1005 may remove the PC5 adaptation layerheader from the PDCP PDU. The remote UE 1005 may transfer the PDCP PDU(e.g., an NR PDCP PDU) to an upper layer based at least in part on theidentified radio access radio bearer associated with the PDCP PDU. As aresult, an end-to-end relay connection can be formed that enables thenetwork entity 1015 to transfer traffic to the remote UE 1005 via theappropriate end-to-end radio bearer via the relay UE 1010.

As indicated above, FIG. 10 is provided as an example. Other examplesmay differ from what is described with respect to FIG. 10 .

FIG. 11 is a diagram illustrating an example 1100 of a privacy updateprocedure, in accordance with various aspects of the present disclosure.As shown, example 1100 includes a remote UE 1105, a relay UE 1110, and anetwork entity 1115. The network entity 1115 may be a base station(e.g., base station 110), a gNB, and/or an NG-RAN, among other examples.As shown by reference number 1120, the remote UE 1105, the relay UE1110, and/or the network entity 1115 may perform a relay connectionsetup (e.g., a sidelink layer 2 relay connection setup). The relayconnection setup may be similar to, or the same as, example 700described above in connection with FIG. 7 . The privacy update proceduredepicted in FIG. 11 may be a remote UE identifier update initiated bythe relay UE 1110. For example, if the relay UE 1110 assigns remote UEidentifiers (e.g., as described above in connection with referencenumber 725 of FIG. 7 ), then the relay UE 1110 may update the remote UEidentifiers for the remote UEs 1105 in communication with the relay UE1110.

As shown by reference number 1125, the relay UE 1110 may initiate anupdate for a remote UE identifier of one or more remote UEs 1105 (e.g.,a RemoteUEIndex update). In some aspects, the relay UE 1110 may initiatea RemoteUEIndex update periodically and/or randomly. For example, therelay UE 1110 may initiate a timer when the relay connection setup iscompleted and/or when a remote UE identifier is assigned to the remoteUE 1105. The relay UE 1110 may initiate a RemoteUEIndex update based atleast in part on an expiry of the timer. In some aspects, the relay UE1110 may initiate a RemoteUEIndex update in order to satisfy a privacyor security requirement of a V2X wireless network (e.g., as defined, orotherwise fixed, by a wireless communication standard, such as a 3GPPSpecification). In some aspects, the relay UE 1110 may initiate aRemoteUEIndex update based at least in part on detecting a triggerevent. A trigger event may be an indication received from the networkentity 1115 and/or from the remote UE 1105. In some aspects, a triggerevent may be an indication to initiate a link identifier update (LIU)with the remote UE 1105. In some aspects, as described above, the relayUE 1110 may initiate a RemoteUEIndex update independently of a LIUtrigger with the remote UE 1105. The RemoteUEIndex update may includethe relay UE 1110 updating or modifying the remote UE identifier of theremote UE 1105 to an updated/modified remote UE identifier.

As shown by reference number 1130, the relay UE 1110 may transmit, tothe remote UE 1105, an indication of the updated/modified remote UEidentifier. In some aspects, the remote UE 1110 may transmit modifiedidentifier information that indicates the updated/modified remote UEidentifier. For example, the relay UE 1110 may transmit theupdated/modified remote UE identifier to the remote UE 1105 via an RRCmessage. In some aspects, the relay UE 1110 may transmit theupdated/modified remote UE identifier to the remote UE 1105 via a linkmodification request message. The remote UE 1105 may receive theindication of the updated/modified remote UE identifier and may updateor modify the remote UE identifier for the remote UE to theupdated/modified remote UE identifier (e.g., from a previous remote UEidentifier). The remote UE 1105 may transmit, to the relay UE 1110, anindication that the remote UE identifier has been successfully completedat the remote UE 1105.

As shown by reference number 1135, the relay UE 1110 may transmit, tothe network entity 1115, an indication of the updated/modified remote UEidentifier for the remote UE 1105. In some aspects, the remote UE 1110may transmit modified identifier information that indicates theupdated/modified remote UE identifier for the remote UE 1105 (and/or oneor more other remote UEs 1105). For example, the relay UE 1110 maytransmit the indication of the updated/modified remote UE identifier forthe remote UE 1105 in an RRC message, such as a sidelink UE information(SUI) message. The network entity 1115 may receive the indication of theupdated/modified remote UE identifier for the remote UE 1105. Thenetwork entity 1115 may update or modify the remote UE identifier forthe remote UE 1105 to the updated/modified remote UE identifier (e.g.,from the previous remote UE identifier for the remote UE 1105).

The relay UE 1110 may update the remote UE identifier in the mannerdescribed above when the control-plane protocol architecture and/or theuser-plane protocol architecture of the relay UE 1110 does not include aPC5 adaptation layer (e.g., control-plane protocol architecture 500and/or the user-plane protocol architecture 600 described above).Alternatively, the relay UE 1110 may update the remote UE identifier inthe manner described above when the control-plane protocol architectureand/or the user-plane protocol architecture of the relay UE 1110 doesinclude a PC5 adaptation layer (e.g., control-plane protocolarchitecture 505 and/or the user-plane protocol architecture 505described above).

In this way, the relay UE 1110 may update the remote UE identifier ofthe remote UE 1105 to ensure that a security or privacy requirement ofthe remote UE 1105 and/or of the V2X network is satisfied. The relay UE1110 may communicate with the remote UE 1105 and/or the network entity1115 to ensure that the remote UE identifier of the remote UE 1105 issuccessfully updated at each device in the relay path.

As indicated above, FIG. 11 is provided as an example. Other examplesmay differ from what is described with respect to FIG. 11 .

FIG. 12 is a diagram illustrating an example 1200 of a privacy updateprocedure, in accordance with various aspects of the present disclosure.As shown, example 1200 includes a remote UE 1205, a relay UE 1210, and anetwork entity 1215. The network entity 1215 may be a base station(e.g., base station 110), a gNB, and/or an NG-RAN, among other examples.As shown by reference number 1220, the remote UE 1205, the relay UE1210, and/or the network entity 1215 may perform a relay connectionsetup (e.g., a sidelink layer 2 relay connection setup). The relayconnection setup may be similar to, or the same as, example 700described above in connection with FIG. 7 . For example, the relayconnection setup may include one or more (or all) of the steps describedabove in connection with FIG. 7 . The privacy update procedure depictedin FIG. 12 may be a remote UE identifier update and/or a PC5 RLC channelidentifier update initiated by the network entity 1215. For example, ifthe network entity 1215 assigns remote UE identifiers (e.g., asdescribed above in connection with reference number 740 of FIG. 7 ),then the network entity 1215 may update the remote UE identifiers forthe remote UEs 1205 in communication with the relay UE 1210.

In some aspects, such as where the control-plane protocol architectureand/or the user-plane protocol architecture of the relay UE 1210 doesnot include a PC5 adaptation layer (e.g., control-plane protocolarchitecture 500 and/or the user-plane protocol architecture 600described above), the network entity 1215 may use a PC5 RLC channelidentifier to identifier a radio access (e.g., Uu) radio bearer (e.g.,an SRB or a DRB) associated with traffic. Therefore, the PC5 RLC channelidentifier needs to be updated to satisfy a security or privacyrequirement of the remote UE 1205 and/or of the V2X network.

As shown by reference number 1225, the network entity 1215 may initiatean update for a remote UE identifier of one or more remote UEs 1205(e.g., a RemoteUEIndex update). In some aspects, the network entity 1215may initiate a RemoteUEIndex update periodically and/or randomly. Forexample, the network entity 1215 may initiate a RemoteUEIndex update ina similar (or the same) manner as the privacy update procedure describedabove. The RemoteUEIndex update may include the network entity 1215updating or modifying the remote UE identifier of the remote UE 1205 toan updated/modified remote UE identifier.

Similarly, the network entity 1215 may update a PC5 RLC channelidentifier for a PC5 RLC channel between the remote UE 1205 and therelay UE 1210 at the same time as, or independently of, initiating theRemoteUEIndex update. The PC5 RLC channel identifier update may includethe network entity 1215 updating or modifying the PC5 RLC channelidentifier for a PC5 RLC channel between the remote UE 1205 and therelay UE 1210 to an updated/modified PC5 RLC channel identifier.

As shown by reference number 1230, the network entity 1215 may transmit,to the relay UE 1210, an indication of the updated/modified remote UEidentifier and/or of the updated/modified PC5 RLC channel identifier. Insome aspects, the network entity 1215 may transmit modified identifierinformation that indicates the updated/modified remote UE identifierand/or of the updated/modified PC5 RLC channel identifier. For example,the network entity 1215 may perform an RRC reconfiguration procedurewith the relay UE 1210 to update or modify the remote UE identifierand/or the PC5 RLC channel identifier. The relay UE 1210 may update ormodify the remote UE identifier for the remote UE 1205 to theupdated/modified remote UE identifier (e.g., from a previous remote UEidentifier). Similarly, the relay UE 1210 may update or modify the PC5RLC channel identifier for the PC5 RLC channel between the remote UE1205 and the relay UE 1210 to the updated/modified PC5 RLC channelidentifier (e.g., from a previous PC5 RLC channel identifier). The relayUE 1210 may transmit, to the network entity 1215, an indication that theremote UE identifier and/or the PC5 RLC channel identifier have beensuccessfully updated at the relay UE 1210 (e.g., in an RRCreconfiguration complete message). The relay UE 1210 may continue tosupport the previous remote UE identifier for the remote UE 1305 afterreceiving the indication of the updated/modified remote UE identifier.For example, the relay UE 1210 may relay communications in accordancewith the previous remote UE identifier for the remote UE 1305 until therelay UE 1210 receives a communication (e.g., from the remote UE 1205 orthe network entity 1215) that includes the updated/modified remote UEidentifier in an adaptation layer header.

As shown by reference number 1235, in some aspects, the relay UE 1210may communicate with the remote UE 1205 to update the remote UEidentifier for the remote UE 1205. For example, after updating theremote UE identifier at the relay UE 1210, the relay UE 1210 mayinitiate a link modification with the relay UE 1210 to update the remoteUE identifier for the remote UE 1205 at the remote UE 1205. For example,the relay UE 1210 may transmit, to the remote UE 1205, an indication ofthe updated/modified remote UE identifier. The remote UE 1205 may updateor modify the remote UE identifier for the remote UE 1205 to theupdated/modified remote UE identifier (e.g., from a previous remote UEidentifier). The remote UE 1205 may transmit, to the relay UE 1210, anindication that the remote UE identifier has been successfully updatedat the remote UE 1205 (e.g., in an RRC message). In some aspects, therelay UE 1210 may transmit the RRC reconfiguration complete message, tothe network entity 1215, after receiving the indication that the remoteUE identifier has been successfully updated at the remote UE 1205.

Alternatively, as shown by reference number 1240, the network entity1215 may communicate with the remote UE 1205, via the relay UE 1210, toupdate the remote UE identifier for the remote UE 1205. In some aspects,the network entity 1215 may transmit modified identifier informationthat indicates the updated/modified remote UE identifier. For example,the network entity 1215 may perform an RRC reconfiguration procedurewith the remote UE 1205 to update or modify the remote UE identifier atthe remote UE 1205. The remote UE 1205 may update or modify the remoteUE identifier for the remote UE 1205 to the updated/modified remote UEidentifier (e.g., from a previous remote UE identifier). The remote UE1205 may transmit, to the network entity 1215, an indication that theremote UE identifier and/or the PC5 RLC channel identifier have beensuccessfully updated at the remote UE 1205 (e.g., in an RRCreconfiguration complete message).

The network entity 1215 may update the remote UE identifier in themanner described above when the control-plane protocol architectureand/or the user-plane protocol architecture of the relay UE 1210 doesnot include a PC5 adaptation layer (e.g., control-plane protocolarchitecture 500 and/or the user-plane protocol architecture 600described above). Alternatively, the network entity 1215 may update theremote UE identifier in the manner described above when thecontrol-plane protocol architecture and/or the user-plane protocolarchitecture of the relay UE 1210 does include a PC5 adaptation layer(e.g., control-plane protocol architecture 505 and/or the user-planeprotocol architecture 505 described above).

In this way, the network entity 1215 may update the remote UE identifierof the remote UE 1205 to ensure that a security or privacy requirementof the remote UE 1205 and/or of the V2X network is satisfied. Thenetwork entity 1215 may communicate with the remote UE 1205 and/or therelay UE 1210 to ensure that the remote UE identifier of the remote UE1205 is successfully updated at each device in the relay path.

As indicated above, FIG. 12 is provided as an example. Other examplesmay differ from what is described with respect to FIG. 12 .

FIG. 13 is a diagram illustrating an example 1300 of a privacy updateprocedure, in accordance with various aspects of the present disclosure.As shown, example 1300 includes a remote UE 1305, a relay UE 1310, and anetwork entity 1315. The network entity 1315 may be a base station(e.g., base station 110), a gNB, and/or an NG-RAN, among other examples.The privacy update procedure depicted in FIG. 13 may be a remote UEbearer identifier update procedure initiated by the network entity 1315.As shown by reference number 1320, the remote UE 1305, the relay UE1310, and/or the network entity 1315 may perform a relay connectionsetup (e.g., a sidelink layer 2 relay connection setup). The relayconnection setup may be similar to, or the same as, example 700described above in connection with FIG. 7 .

As shown by reference number 1325, the network entity 1315 may initiatean update for a remote UE bearer identifier of one or more radio access(e.g., Uu) radio bearers of the remote UE 1305 (e.g., a RemoteUE bearerID update). In some aspects, the network entity 1315 may initiate aRemoteUE bearer ID update periodically and/or randomly. For example, thenetwork entity 1315 may initiate a RemoteUE bearer ID update in asimilar (or the same) manner as the privacy update procedures describedabove.

The RemoteUE bearer ID update may include the network entity 1315updating or modifying the remote UE bearer identifier of a DRB or SRB ofthe remote UE 1305 to an updated/modified remote UE bearer identifier(e.g., a new C-RNTI for the DRB/SRB or a new temporary identifier). Insome aspects, the network entity 1315 may perform the RemoteUE bearer IDupdate at the same time as a remote UE identifier for the remote UE 1305is updated (e.g., as described above in connection with FIGS. 11 and/or12 ). In some aspects, the network entity 1315 may perform the RemoteUEbearer ID update independently from the remote UE identifier update forthe remote UE 1305.

As shown by reference number 1330, the network entity 1315 may transmit,to the relay UE 1310, an indication of the updated/modified remote UEbearer identifier. In some aspects, the network entity 1315 may transmitmodified identifier information that indicates the updated/modifiedremote UE identifier and/or of the updated/modified remote UE beareridentifier. For example, the network entity 1315 may perform an RRCreconfiguration procedure with the relay UE 1310 to update or modify theremote UE bearer identifier. The relay UE 1310 may update or modify theremote UE bearer identifier for the radio bearer of the remote UE 1305(e.g., from a previous remote UE bearer identifier). The relay UE 1310may transmit, to the network entity 1315, an indication that the remoteUE bearer identifier has been successfully updated at the relay UE 1310(e.g., in an RRC reconfiguration complete message).

As shown by reference number 1335, the relay UE 1310 may continue tosupport the previous remote UE bearer identifier for the radio bearer ofthe remote UE 1305 after receiving the indication of theupdated/modified remote UE bearer identifier. For example, the relay UE1310 may continue to support the previous remote UE bearer identifierfor the radio bearer of the remote UE 1305 to enable the remote UEbearer identifier for the radio bearer to be updated at the remote UE1305. For example, the relay UE 1310 may transmit traffic to the relayUE 1310 after the relay UE 1310 has received the indication of theupdated/modified remote UE bearer identifier, but before the remote UEbearer identifier for the radio bearer has been updated at the remote UE1305 (e.g., as described below). Therefore, the traffic may include(e.g., in a PC5 adaptation layer header) an indication of the previousremote UE bearer identifier for the radio bearer. The relay UE 1310 mayroute the traffic according to the mapping information for the previousremote UE bearer identifier for the radio bearer (e.g., to a correct UuRLC channel) to ensure that the traffic is successfully relayed to thenetwork entity 1315. This may ensure that traffic is not dropped or lostin a scenario where the relay UE 1310 has been updated with theupdated/modified remote UE bearer identifier, but the remote UE 1305 hasnot been updated with the updated/modified remote UE bearer identifier.The relay UE 1310 may continue to support the previous remote UE beareridentifier for the radio bearer of the remote UE 1305 until the relay UE1310 receives traffic from the remote UE 1305 (or the network entity1315) that includes (e.g., in an adaptation layer header) an indicationof the updated/modified remote UE bearer identifier.

As shown by reference number 1340, the network entity 1315 maycommunicate with the remote UE 1305, via the relay UE 1310, to updatethe remote UE bearer identifier for radio bearer of the remote UE 1305.In some aspects, the network entity 1315 may transmit modifiedidentifier information that indicates the updated/modified remote UEidentifier and/or of the updated/modified remote UE bearer identifier.For example, the network entity 1315 may perform an RRC reconfigurationprocedure with the remote UE 1305 to update or modify the remote UEbearer identifier at the remote UE 1305. The remote UE 1305 may updateor modify the remote UE bearer identifier for the radio bearer to theupdated/modified remote UE bearer identifier (e.g., from the previousremote UE bearer identifier). The remote UE 1305 may transmit, to thenetwork entity 1315, an indication that the remote UE bearer identifierhas been successfully updated at the remote UE 1305 (e.g., in an RRCreconfiguration complete message).

In this way, the network entity 1315 may update the remote UE beareridentifier of radio bearers of the remote UE 1305 to ensure that asecurity or privacy requirement of the remote UE 1305 and/or of the V2Xnetwork is satisfied. The network entity 1315 may communicate with theremote UE 1305 and/or the relay UE 1310 to ensure that the remote UEbearer identifier is successfully updated at each device in the relaypath.

As indicated above, FIG. 13 is provided as an example. Other examplesmay differ from what is described with respect to FIG. 13 .

FIG. 14 is a diagram illustrating an example process 1400 performed, forexample, by a relay UE, in accordance with various aspects of thepresent disclosure. Example process 1400 is an example where the relayUE (e.g., UE 120, relay UE 710, relay UE 910, relay UE 1010, relay UE1110, relay UE 1210, and/or relay UE 1310) performs operationsassociated with a relay adaptation layer configuration for a sidelinkinterface.

As shown in FIG. 14 , in some aspects, process 1400 may includeestablishing a sidelink unicast link with a remote UE via a sidelinksignaling interface (block 1410). For example, the relay UE (e.g., usingreception component 1702 and/or transmission component 1704, depicted inFIG. 17 ) may establish a sidelink unicast link with a remote UE via asidelink signaling interface, as described above.

As further shown in FIG. 14 , in some aspects, process 1400 may includeidentifying configuration information for an adaptation layer of thesidelink signaling interface, the configuration information including atleast one of: a remote UE identifier for the remote UE identifying thesidelink unicast link between the remote UE and the relay UE for a relayservice, bearer identifier information identifying one or more bearersbetween the remote UE and a network entity associated with the relayservice, RLC channel mapping information, wherein the RLC channelmapping information includes a mapping between a bearer identifier andone or more RLC channels of the sidelink unicast link and one or moreRLC channels of a link with the network entity, or data routinginformation associated with the relay service (block 1420). For example,the relay UE (e.g., using reception component 1702 and/or determinationcomponent 1708, depicted in FIG. 17 ) may identify configurationinformation for an adaptation layer of the sidelink signaling interface,the configuration information including at least one of: a remote UEidentifier for the remote UE identifying the sidelink unicast linkbetween the remote UE and the relay UE for a relay service, beareridentifier information identifying one or more bearers between theremote UE and a network entity associated with the relay service, RLCchannel mapping information, wherein the RLC channel mapping informationincludes a mapping between a bearer identifier and one or more RLCchannels of the sidelink unicast link and one or more RLC channels of alink with the network entity, or data routing information associatedwith the relay service, as described above.

As further shown in FIG. 14 , in some aspects, process 1400 may includerelaying communications between the remote UE and the network entitybased at least in part on the configuration information for theadaptation layer of the sidelink signaling interface (block 1430). Forexample, the relay UE (e.g., using reception component 1702 and/ortransmission component 1704, depicted in FIG. 17 ) may relaycommunications between the remote UE and the network entity based atleast in part on the configuration information for the adaptation layerof the sidelink signaling interface, as described above.

Process 1400 may include additional aspects, such as any single aspector any combination of aspects described below and/or in connection withone or more other processes described elsewhere herein.

In a first aspect, the sidelink signaling interface is a PC5 interfaceand the link with the network entity is via a Uu interface.

In a second aspect, alone or in combination with the first aspect,relaying communications between the remote UE and the network entity isbased at least in part on a sidelink signaling interface adaptationlayer header, wherein the sidelink signaling interface adaptation layerheader indicates at least one of the remote UE identifier of the remoteUE, a bearer identifier of a bearer between the remote UE and a networkentity associated with the relay service, or a path identifier for thedata routing associated with the relay service.

In a third aspect, alone or in combination with one or more of the firstand second aspects, the remote UE identifier corresponds to a uniqueindex assigned to each remote UE, of a plurality of remote UEs, incommunication with the relay UE via respective sidelink unicast links.

In a fourth aspect, alone or in combination with one or more of thefirst through third aspects, process 1400 includes assigning remote UEidentifiers to each remote UE, of a plurality of remote UEs, incommunication with the relay UE.

In a fifth aspect, alone or in combination with one or more of the firstthrough fourth aspects, establishing the sidelink unicast link with theremote UE comprises assigning the remote UE identifier to the remote UEincluding a unique index associated with the sidelink unicast link, andtransmitting, to the remote UE, an indication of the remote UEidentifier via a sidelink signaling interface message.

In a sixth aspect, alone or in combination with one or more of the firstthrough fifth aspects, process 1400 includes assigning a unique indexassociated with the sidelink unicast link, and transmitting informationindicating the unique index to the network entity via a radio resourcecontrol message.

In a seventh aspect, alone or in combination with one or more of thefirst through sixth aspects, identifying the configuration informationcomprises receiving, from the network entity, a relaying configurationindicating at least part of the configuration information.

In an eighth aspect, alone or in combination with one or more of thefirst through third aspects, identifying the configuration informationcomprises receiving, from the network entity, an indication of theremote UE identifier via a radio resource control message.

In a ninth aspect, alone or in combination with the eighth aspect,receiving, from the network entity, the indication of the remote UEidentifier comprises receiving, from the network entity, an indicationof remote UE identifiers for each remote UE, of a plurality of remoteUEs, in communication with the relay UE.

In a tenth aspect, alone or in combination with one or more of theeighth through ninth aspects, receiving, from the network entity, theindication of the remote UE identifier comprises receiving, from thenetwork entity, an indication of a C-RNTI for each remote UE, of aplurality of remote UEs, in communication with the relay UE.

In an eleventh aspect, alone or in combination with one or more of theeighth through ninth aspects, receiving, from the network entity, theindication of the remote UE identifier comprises receiving, from thenetwork entity, an indication of a temporary identifier for each remoteUE, of a plurality of remote UEs, in communication with the relay UE,wherein the temporary identifier is unique among the plurality of remoteUEs in communication with the relay UE.

In a twelfth aspect, alone or in combination with one or more of thefirst through eleventh aspects, identifying the configurationinformation comprises receiving, from the network entity, the beareridentifier information including an indication of a bearer identifieridentifying a bearer between the remote UE and the network entityassociated with the relay service, wherein the bearer identifier is thesame as a DRB identifier of a DRB between the remote UE and the networkentity or the same as an SRB identifier of an SRB between the remote UEand the network entity.

In a thirteenth aspect, alone or in combination with one or more of thefirst through eleventh aspects, identifying the configurationinformation comprises receiving, from the network entity, the beareridentifier information including an indication of a bearer identifieridentifying a bearer between the remote UE and the network entityassociated with the relay service, wherein the bearer identifier is aunique identifier associated with the bearer between the remote UE andthe network entity to be used with the relay service.

In a fourteenth aspect, alone or in combination with one or more of thefirst through thirteenth aspects, identifying the configurationinformation comprises receiving, from the network entity, an indicationof a default bearer identifier identifying an SRB associated with radioresource control messages.

In a fifteenth aspect, alone or in combination with the fourteenthaspect, process 1400 includes receiving, from the remote UE via thesidelink unicast link, a radio resource control setup request message,wherein the radio resource control setup request message includes thedefault bearer identifier, determining that the radio resource controlsetup request message is to be transmitted using the SRB associated withradio resource control messages based at least in part on the defaultbearer identifier, and relaying the radio resource control setup requestmessage to the network entity via an RLC channel for the SRB associatedwith radio resource control messages.

In a sixteenth aspect, alone or in combination with the fifteenthaspect, process 1400 includes receiving, from the network entity, arelaying configuration via a radio resource control message indicatingthe bearer identifier based at least in part on relaying the radioresource control setup request message to the network entity, andrelaying the radio resource control message indicating the beareridentifier to the remote UE based at least in part on the relayingconfiguration.

In a seventeenth aspect, alone or in combination with one or more of thefirst through sixteenth aspects, relaying communications between theremote UE and the network entity comprises receiving, from the remote UEvia the sidelink unicast link, a PDCP PDU that includes an adaptationlayer header that indicates at least one of: the remote UE identifierassociated with the remote UE, or a bearer identifier, identifying anRLC channel of the link with the network entity based at least in parton the RLC channel mapping information and the bearer identifier,generating a Uu PDCP PDU for the link with the network entity thatincludes an adaptation layer header that indicates at least one of: theremote UE identifier associated with the remote UE, or the beareridentifier, and transmitting, to the network entity via the RLC channel,the Uu PDCP PDU for the link with the network entity that includes theadaptation layer header.

In an eighteenth aspect, alone or in combination with one or more of thefirst through seventeenth aspects, relaying communications between theremote UE and the network entity comprises receiving, from the networkentity, a Uu PDCP PDU that includes an adaptation layer header thatindicates at least one of: the remote UE identifier associated with theremote UE, or a bearer identifier, identifying an RLC channel of thesidelink unicast link based at least in part on the RLC channel mappinginformation and the bearer identifier, generating a PDCP PDU for thesidelink unicast link that includes an adaptation layer header thatindicates at least one of: the remote UE identifier associated with theremote UE, or the bearer identifier, and transmitting, to the remote UEvia the RLC channel, the PDCP PDU for the sidelink unicast link thatincludes the adaptation layer header.

In a nineteenth aspect, alone or in combination with one or more of thefirst through eighteenth aspects, process 1400 includes performing aprivacy update procedure with at least one of the remote UE or thenetwork entity, wherein the privacy update procedure includes updatinginformation included in configuration information.

In a twentieth aspect, alone or in combination with the nineteenthaspect, performing the privacy update procedure comprises performing theprivacy update procedure according to a periodic schedule.

In a twenty-first aspect, alone or in combination with one or more ofthe nineteenth through twentieth aspects, performing the privacy updateprocedure comprises detecting a trigger event associated with a privacyupdate, and performing the privacy update procedure based at least inpart on detecting the trigger event.

In a twenty-second aspect, alone or in combination with one or more ofthe nineteenth through twenty-first aspects, performing the privacyupdate procedure comprises modifying the remote UE identifier for theremote UE to a modified remote UE identifier, communicating, with theremote UE via the sidelink unicast link, to indicate the modified remoteUE identifier, and communicating, with the network entity, to indicatethe modified remote UE identifier.

In a twenty-third aspect, alone or in combination with one or more ofthe nineteenth through twenty-second aspects, performing the privacyupdate procedure comprises receiving, from the network entity, anindication of modified identifier information for at least one of theadaptation layer of the sidelink signaling interface or the adaptionlayer of the link with the network entity, modifying the configurationinformation based at least in part on the modified identifierinformation, communicating, with the remote UE via the sidelink unicastlink, to indicate the modified identifier information, andcommunicating, with the network entity, to indicate that theconfiguration information for the sidelink signaling interface has beenmodified at the relay UE and the remote UE based at least in part oncommunicating with the remote UE to indicate the modified identifierinformation.

In a twenty-fourth aspect, alone or in combination with the twenty-thirdaspect, process 1400 includes receiving, from the remote UE, a signalthat includes a previous identifier, that is modified by the modifiedidentifier information to a modified identifier, in an adaptation layerheader of the signal after receiving the indication of the modifiedidentifier information and prior to receiving a signal that includes anindication of the modified identifier, and relaying, to the networkentity via an RLC channel, the signal based at least in part on theprevious identifier.

In a twenty-fifth aspect, alone or in combination with one or more ofthe twenty-third through twenty-fourth aspects, process 1400 includesreceiving, from the remote UE or the network entity, a signal thatincludes an indication of a modified identifier, indicated in themodified identifier information, in an adaptation layer header of thesignal, and refraining from relaying communications using a previousidentifier based at least in part on receiving the signal that includesthe indication of the modified identifier in the adaptation layer headerof the signal.

Although FIG. 14 shows example blocks of process 1400, in some aspects,process 1400 may include additional blocks, fewer blocks, differentblocks, or differently arranged blocks than those depicted in FIG. 14 .Additionally, or alternatively, two or more of the blocks of process1400 may be performed in parallel.

FIG. 15 is a diagram illustrating an example process 1500 performed, forexample, by a network entity, in accordance with various aspects of thepresent disclosure. Example process 1500 is an example where the networkentity (e.g., a base station 110 or another network entity describedherein) performs operations associated with a relay adaptation layerconfiguration for a sidelink interface.

As shown in FIG. 15 , in some aspects, process 1500 may includecommunicating, with a relay UE and a remote UE, configurationinformation for an adaptation layer of a sidelink signaling interfacebetween the relay UE and the remote UE, the configuration informationincluding at least one of: a remote UE identifier for the remote UEidentifying a sidelink unicast link between the remote UE and the relayUE for a relay service, bearer identifier information identifying one ormore bearers between the remote UE and the network entity associatedwith the relay service, RLC channel mapping information, wherein the RLCchannel mapping information includes a mapping between a beareridentifier and one or more RLC channels of a sidelink unicast link andone or more RLC channels of a link with the relay UE, or data routinginformation associated with the relay service (block 1510). For example,the network entity (e.g., using reception component 1802 and/ortransmission component 1804, depicted in FIG. 18 ) may communicate, witha relay UE and a remote UE, configuration information for an adaptationlayer of a sidelink signaling interface between the relay UE and theremote UE, the configuration information including at least one of: aremote UE identifier for the remote UE identifying a sidelink unicastlink between the remote UE and the relay UE for a relay service, beareridentifier information identifying one or more bearers between theremote UE and the network entity associated with the relay service, RLCchannel mapping information, wherein the RLC channel mapping informationincludes a mapping between a bearer identifier and one or more RLCchannels of a sidelink unicast link and one or more RLC channels of alink with the relay UE, or data routing information associated with therelay service, as described above.

As further shown in FIG. 15 , in some aspects, process 1500 may includecommunicating with the remote UE via the relay UE based at least in parton the configuration information (block 1520). For example, the networkentity (e.g., using reception component 1802 and/or transmissioncomponent 1804, depicted in FIG. 18 ) may communicate with the remote UEvia the relay UE based at least in part on the configurationinformation, as described above.

Process 1500 may include additional aspects, such as any single aspector any combination of aspects described below and/or in connection withone or more other processes described elsewhere herein.

In a first aspect, the sidelink signaling interface is a PC5 interfaceand the link with the relay UE is via a Uu interface.

In a second aspect, alone or in combination with the first aspect, theremote UE identifier corresponds to a unique index assigned to eachremote UE, of a plurality of remote UEs, in communication with the relayUE via respective sidelink unicast links.

In a third aspect, alone or in combination with one or more of the firstand second aspects, communicating the configuration informationcomprises receiving, from the relay UE, an indication of remote UEidentifiers for each remote UE, of a plurality of remote UEs, incommunication with the relay UE via a radio resource control message.

In a fourth aspect, alone or in combination with one or more of thefirst and second aspects, process 1500 includes assigning remote UEidentifiers to each remote UE, of a plurality of remote UEs, incommunication with the relay UE.

In a fifth aspect, alone or in combination with the fourth aspect,assigning remote UE identifiers to each remote UE, of the plurality ofremote UEs, in communication with the relay UE comprises assigning, fora remote UE of the plurality of remote UEs, the remote UE identifier asa C-RNTI identifying a sidelink unicast link between the remote UE andthe relay UE.

In a sixth aspect, alone or in combination with the fourth aspect,assigning remote UE identifiers to each remote UE, of the plurality ofremote UEs, in communication with the relay UE comprises assigning, fora remote UE of the plurality of remote UEs, a temporary identifier forthe remote UE, wherein the temporary identifier is unique among theplurality of remote UEs in communication with the relay UE.

In a seventh aspect, alone or in combination with one or more of thefourth through sixth aspects, process 1500 includes transmitting, to theremote UE via the relay UE, an indication of the remote UE identifierfor the remote UE via a radio resource control message.

In an eighth aspect, alone or in combination with one or more of thefourth through seventh aspects, communicating the configurationinformation comprises transmitting, to the relay UE, a relayingconfiguration via a radio resource control message, wherein the relayingconfiguration indicates the remote UE identifiers for each remote UE, ofthe plurality of remote UEs, in communication with the relay UE.

In a ninth aspect, alone or in combination with one or more of the firstthrough eighth aspects, process 1500 includes assigning a beareridentifier for each bearer of the one or more bearers between the remoteUE and a network entity associated with the relay service.

In a tenth aspect, alone or in combination with the ninth aspect, abearer identifier for a bearer, of the one or more bearers, is same as aDRB identifier of a DRB between the remote UE and the network entity orthe same as an SRB identifier of an SRB between the remote UE and thenetwork entity.

In an eleventh aspect, alone or in combination with the ninth aspect, abearer identifier for a bearer, of the one or more bearers, is a uniqueidentifier associated with the bearer between the remote UE and thenetwork entity to be used with the relay service.

In a twelfth aspect, alone or in combination with one or more of theninth through eleventh aspects, process 1500 includes transmitting, tothe remote UE via the relay UE, the bearer identifier information via aradio resource control message, wherein the bearer identifierinformation indicates the bearer identifier for each bearer of the oneor more bearers between the remote UE and a network entity associatedwith the relay service, and for each bearer identifier, an indication ofa DRB or an SRB associated with the bearer identifier.

In a thirteenth aspect, alone or in combination with one or more of theninth through twelfth aspects, communicating the configurationinformation comprises transmitting, to the relay UE, the beareridentifier information via a radio resource control message, wherein thebearer identifier information indicates the bearer identifier for eachbearer of the one or more bearers between the remote UE and a networkentity associated with the relay service, and for each beareridentifier, an indication of a DRB or an SRB associated with the beareridentifier.

In a fourteenth aspect, alone or in combination with one or more of thefirst through thirteenth aspects, communicating the configurationinformation comprises transmitting, to the relay UE and the remote UEvia the relay UE, an indication of a default bearer identifieridentifying an SRB associated with radio resource control messages.

In a fifteenth aspect, alone or in combination with the fourteenthaspect, the SRB associated with radio resource control messages is SRB0.

In a sixteenth aspect, alone or in combination with one or more of thefirst through fifteenth aspects, communicating with the remote UE viathe relay UE comprises receiving, from the relay UE, an adaptation layerPDU, determining an SRB or a DRB associated with the remote UE based atleast in part on a header of the adaptation layer PDU, removing theheader of the adaptation layer PDU, and transferring a New Radio PDCPPDU of the adaptation layer PDU to an upper layer.

In a seventeenth aspect, alone or in combination with one or more of thefirst through sixteenth aspects, communicating with the remote UE viathe relay UE comprises determining the remote UE identifier of theremote UE associated with a sidelink unicast link for the remote UE,determining a bearer identifier of the remote UE corresponding to aradio access bearer of the remote UE, determining a radio access RLCchannel between the relay UE and the network entity corresponding to thebearer identifier, generating an adaptation layer header including atleast one of the remote UE identifier, the bearer identifier, or a pathidentifier, and transmitting, to the relay UE, an adaptation layer PDUwith the adaptation layer header on the radio access RLC channel betweenthe relay UE and the network entity.

In an eighteenth aspect, alone or in combination with one or more of thefirst through seventeenth aspects, process 1500 includes performing aprivacy update procedure with at least one of the remote UE or the relayUE, wherein the privacy update procedure includes updating informationincluded in configuration information.

In a nineteenth aspect, alone or in combination with the eighteenthaspect, performing the privacy update procedure comprises performing theprivacy update procedure according to a periodic schedule.

In a twentieth aspect, alone or in combination with one or more of theeighteenth through nineteenth aspects, performing the privacy updateprocedure comprises detecting a trigger event associated with a privacyupdate, and performing the privacy update procedure based at least inpart on detecting the trigger event.

In a twenty-first aspect, alone or in combination with one or more ofthe eighteenth through twentieth aspects, performing the privacy updateprocedure comprises modifying one or more identifiers for an adaptionlayer header for the relay service, communicating, with the remote UEvia the relay UE, to indicate modified identifier information thatindicates the one or more modified identifiers, and communicating, withthe relay UE, to indicate the modified identifier information thatindicates the one or more modified identifiers.

Although FIG. 15 shows example blocks of process 1500, in some aspects,process 1500 may include additional blocks, fewer blocks, differentblocks, or differently arranged blocks than those depicted in FIG. 15 .Additionally, or alternatively, two or more of the blocks of process1500 may be performed in parallel.

FIG. 16 is a diagram illustrating an example process 1600 performed, forexample, by a remote UE, in accordance with various aspects of thepresent disclosure. Example process 1600 is an example where the remoteUE (e.g., UE 120) performs operations associated with a relay adaptationlayer configuration for a sidelink interface.

As shown in FIG. 16 , in some aspects, process 1600 may includeestablishing a sidelink unicast link with a relay UE via a sidelinksignaling interface (block 1610). For example, the remote UE (e.g.,using reception component 1902 and/or transmission component 1904,depicted in FIG. 19 ) may establish a sidelink unicast link with a relayUE via a sidelink signaling interface, as described above.

As further shown in FIG. 16 , in some aspects, process 1600 may includereceiving configuration information for an adaptation layer of thesidelink signaling interface, the configuration information including atleast one of: a remote UE identifier for the remote UE identifying thesidelink unicast link between the remote UE and the relay UE for a relayservice, bearer identifier information identifying one or more bearersbetween the remote UE and a network entity associated with the relayservice, or RLC channel mapping information, wherein the RLC channelmapping information includes a mapping between a bearer identifier andone or more RLC channels of the sidelink unicast link and one or moreRLC channels of a link with the network entity (block 1620). Forexample, the remote UE (e.g., using reception component 1902, depictedin FIG. 19 ) may receive configuration information for an adaptationlayer of the sidelink signaling interface, the configuration informationincluding at least one of: a remote UE identifier for the remote UEidentifying the sidelink unicast link between the remote UE and therelay UE for a relay service, bearer identifier information identifyingone or more bearers between the remote UE and a network entityassociated with the relay service, or RLC channel mapping information,wherein the RLC channel mapping information includes a mapping between abearer identifier and one or more RLC channels of the sidelink unicastlink and one or more RLC channels of a link with the network entity, asdescribed above.

As further shown in FIG. 16 , in some aspects, process 1600 may includecommunicating with the network entity via the relay UE based at least inpart on the configuration information (block 1630). For example, theremote UE (e.g., using reception component 1902 and/or transmissioncomponent 1904, depicted in FIG. 19 ) may communicate with the networkentity via the relay UE based at least in part on the configurationinformation, as described above.

Process 1600 may include additional aspects, such as any single aspector any combination of aspects described below and/or in connection withone or more other processes described elsewhere herein.

In a first aspect, the sidelink signaling interface is a PC5 interfaceand the link with the network entity is via a Uu interface.

In a second aspect, alone or in combination with the first aspect, theremote UE identifier corresponds to a unique index assigned to theremote UE.

In a third aspect, alone or in combination with one or more of the firstand second aspects, receiving the configuration information comprisesreceiving, from the relay UE, an indication of the remote UE identifierfor the remote UE.

In a fourth aspect, alone or in combination with one or more of thefirst and second aspects, receiving the configuration informationcomprises receiving, from the network entity via the relay UE, anindication of the remote UE identifier for the remote UE via a radioresource control message.

In a fifth aspect, alone or in combination with the fourth aspect, theremote UE identifier is the same as a C-RNTI identifying the sidelinkunicast link between the remote UE and the relay UE.

In a sixth aspect, alone or in combination with the fourth aspect, theremote UE identifier is a temporary identifier for the remote UE,wherein the temporary identifier is unique among a plurality of remoteUEs in communication with the relay UE.

In a seventh aspect, alone or in combination with one or more of thefirst through sixth aspects, process 1600 includes receiving, from thenetwork entity via the relay UE, the bearer identifier information via aradio resource control message, wherein the bearer identifierinformation indicates the bearer identifier for each bearer of the oneor more bearers between the remote UE and a network entity associatedwith the relay service, and for each bearer identifier, an indication ofa DRB or an SRB associated with the bearer identifier.

In an eighth aspect, alone or in combination with one or more of thefirst through seventh aspects, receiving the configuration informationcomprises receiving, from the network entity via the relay UE, anindication of a default bearer identifier identifying an SRB associatedwith radio resource control messages.

In a ninth aspect, alone or in combination with the eighth aspect, theSRB associated with radio resource control messages is SRB0.

In a tenth aspect, alone or in combination with one or more of theeighth and ninth aspects, process 1600 includes transmitting, to thenetwork entity via the relay UE, a resource control message includingthe default bearer identifier identifying the SRB associated with radioresource control messages.

In an eleventh aspect, alone or in combination with one or more of thefirst through tenth aspects, communicating with the network entity viathe relay UE comprises receiving, from the relay UE, an adaptation layerPDU, determining an SRB or a DRB associated with the remote UE based atleast in part on a header of the adaptation layer PDU, removing theheader of the adaptation layer PDU, and transferring a New Radio PDCPPDU of the adaptation layer PDU to an upper layer.

In a twelfth aspect, alone or in combination with one or more of thefirst through eleventh aspects, communicating with the network entityvia the relay UE comprises determining the remote UE identifier of theremote UE associated with the sidelink unicast link for the remote UE,determining a bearer identifier of the remote UE corresponding to aradio access bearer of the remote UE, determining a sidelink RLC channelbetween the relay UE and the remote UE corresponding to the beareridentifier, generating an adaptation layer header including at least oneof the remote UE identifier, the bearer identifier, or a pathidentifier, and transmitting, to the relay UE, an adaptation layer PDUwith the adaptation layer header on the sidelink RLC channel between therelay UE and the remote UE.

In a thirteenth aspect, alone or in combination with one or more of thefirst through twelfth aspects, process 1600 includes performing aprivacy update procedure with at least one of the network entity or therelay UE, wherein the privacy update procedure includes updatinginformation included in configuration information.

In a fourteenth aspect, alone or in combination with the thirteenthaspect, performing the privacy update procedure comprises performing theprivacy update procedure according to a periodic schedule.

In a fifteenth aspect, alone or in combination with one or more of thethirteenth through fourteenth aspects, performing the privacy updateprocedure comprises detecting a trigger event associated with a privacyupdate, and performing the privacy update procedure based at least inpart on detecting the trigger event.

In a sixteenth aspect, alone or in combination with one or more of thethirteenth through fifteenth aspects, performing the privacy updateprocedure comprises receiving, from the network entity via the relay UEor from the relay UE, an indication of modified identifier informationindicating one or more modified identifiers for the adaptation layer,modifying the configuration information based at least in part on themodified identifier information, and communicating, with the relay UE,to indicate that the one or more modified identifiers for the adaptationlayer been modified at the remote UE.

Although FIG. 16 shows example blocks of process 1600, in some aspects,process 1600 may include additional blocks, fewer blocks, differentblocks, or differently arranged blocks than those depicted in FIG. 16 .Additionally, or alternatively, two or more of the blocks of process1600 may be performed in parallel.

FIG. 17 is a block diagram of an example apparatus 1700 for wirelesscommunication. The apparatus 1700 may be a relay UE, or a relay UE mayinclude the apparatus 1700. In some aspects, the apparatus 1700 includesa reception component 1702 and a transmission component 1704, which maybe in communication with one another (for example, via one or more busesand/or one or more other components). As shown, the apparatus 1700 maycommunicate with another apparatus 1706 (such as a UE, a base station,or another wireless communication device) using the reception component1702 and the transmission component 1704. As further shown, theapparatus 1700 may include a determination component 1708, among otherexamples.

In some aspects, the apparatus 1700 may be configured to perform one ormore operations described herein in connection with FIGS. 7-13 .Additionally, or alternatively, the apparatus 1700 may be configured toperform one or more processes described herein, such as process 1400 ofFIG. 14 , or a combination thereof. In some aspects, the apparatus 1700and/or one or more components shown in FIG. 17 may include one or morecomponents of the UE described above in connection with FIG. 2 .Additionally, or alternatively, one or more components shown in FIG. 17may be implemented within one or more components described above inconnection with FIG. 2 . Additionally, or alternatively, one or morecomponents of the set of components may be implemented at least in partas software stored in a memory. For example, a component (or a portionof a component) may be implemented as instructions or code stored in anon-transitory computer-readable medium and executable by a controlleror a processor to perform the functions or operations of the component.

The reception component 1702 may receive communications, such asreference signals, control information, data communications, or acombination thereof, from the apparatus 1706. The reception component1702 may provide received communications to one or more other componentsof the apparatus 1700. In some aspects, the reception component 1702 mayperform signal processing on the received communications (such asfiltering, amplification, demodulation, analog-to-digital conversion,demultiplexing, deinterleaving, de-mapping, equalization, interferencecancellation, or decoding, among other examples), and may provide theprocessed signals to the one or more other components of the apparatus1706. In some aspects, the reception component 1702 may include one ormore antennas, a demodulator, a MIMO detector, a receive processor, acontroller/processor, a memory, or a combination thereof, of the UEdescribed above in connection with FIG. 2 .

The transmission component 1704 may transmit communications, such asreference signals, control information, data communications, or acombination thereof, to the apparatus 1706. In some aspects, one or moreother components of the apparatus 1706 may generate communications andmay provide the generated communications to the transmission component1704 for transmission to the apparatus 1706. In some aspects, thetransmission component 1704 may perform signal processing on thegenerated communications (such as filtering, amplification, modulation,digital-to-analog conversion, multiplexing, interleaving, mapping, orencoding, among other examples), and may transmit the processed signalsto the apparatus 1706. In some aspects, the transmission component 1704may include one or more antennas, a modulator, a transmit MIMOprocessor, a transmit processor, a controller/processor, a memory, or acombination thereof, of the UE described above in connection with FIG. 2. In some aspects, the transmission component 1704 may be co-locatedwith the reception component 1702 in a transceiver.

The reception component 1702 and/or the transmission component 1704 mayestablish a sidelink unicast link with a remote UE via a sidelinksignaling interface. The reception component 1702 and/or thedetermination component 1708 may identify configuration information foran adaptation layer of the sidelink signaling interface, theconfiguration information including at least one of a remote UEidentifier for the remote UE identifying the sidelink unicast linkbetween the remote UE and the relay UE for a relay service, beareridentifier information identifying one or more bearers between theremote UE and a network entity associated with the relay service, RLCchannel mapping information, wherein the RLC channel mapping informationincludes a mapping between a bearer identifier and one or more RLCchannels of the sidelink unicast link and one or more RLC channels of alink with the network entity, or data routing information associatedwith the relay service. The reception component 1702 and/or thetransmission component 1704 may relay communications between the remoteUE and the network entity based at least in part on the configurationinformation for the adaptation layer of the sidelink signalinginterface.

The number and arrangement of components shown in FIG. 17 are providedas an example. In practice, there may be additional components, fewercomponents, different components, or differently arranged componentsthan those shown in FIG. 17 . Furthermore, two or more components shownin FIG. 17 may be implemented within a single component, or a singlecomponent shown in FIG. 17 may be implemented as multiple, distributedcomponents. Additionally, or alternatively, a set of (one or more)components shown in FIG. 17 may perform one or more functions describedas being performed by another set of components shown in FIG. 17 .

FIG. 18 is a block diagram of an example apparatus 1800 for wirelesscommunication. The apparatus 1800 may be a base station (or a networkentity), or a base station (or a network entity) may include theapparatus 1800. In some aspects, the apparatus 1800 includes a receptioncomponent 1802 and a transmission component 1804, which may be incommunication with one another (for example, via one or more busesand/or one or more other components). As shown, the apparatus 1800 maycommunicate with another apparatus 1806 (such as a UE, a base station,or another wireless communication device) using the reception component1802 and the transmission component 1804. As further shown, theapparatus 1800 may a determination component 1808, among other examples.

In some aspects, the apparatus 1800 may be configured to perform one ormore operations described herein in connection with FIGS. 7-13 .Additionally, or alternatively, the apparatus 1800 may be configured toperform one or more processes described herein, such as process 1500 ofFIG. 15 , or a combination thereof. In some aspects, the apparatus 1800and/or one or more components shown in FIG. 18 may include one or morecomponents of the base station described above in connection with FIG. 2. Additionally, or alternatively, one or more components shown in FIG.18 may be implemented within one or more components described above inconnection with FIG. 2 . Additionally, or alternatively, one or morecomponents of the set of components may be implemented at least in partas software stored in a memory. For example, a component (or a portionof a component) may be implemented as instructions or code stored in anon-transitory computer-readable medium and executable by a controlleror a processor to perform the functions or operations of the component.

The reception component 1802 may receive communications, such asreference signals, control information, data communications, or acombination thereof, from the apparatus 1806. The reception component1802 may provide received communications to one or more other componentsof the apparatus 1800. In some aspects, the reception component 1802 mayperform signal processing on the received communications (such asfiltering, amplification, demodulation, analog-to-digital conversion,demultiplexing, deinterleaving, de-mapping, equalization, interferencecancellation, or decoding, among other examples), and may provide theprocessed signals to the one or more other components of the apparatus1806. In some aspects, the reception component 1802 may include one ormore antennas, a demodulator, a MIMO detector, a receive processor, acontroller/processor, a memory, or a combination thereof, of the basestation described above in connection with FIG. 2 .

The transmission component 1804 may transmit communications, such asreference signals, control information, data communications, or acombination thereof, to the apparatus 1806. In some aspects, one or moreother components of the apparatus 1806 may generate communications andmay provide the generated communications to the transmission component1804 for transmission to the apparatus 1806. In some aspects, thetransmission component 1804 may perform signal processing on thegenerated communications (such as filtering, amplification, modulation,digital-to-analog conversion, multiplexing, interleaving, mapping, orencoding, among other examples), and may transmit the processed signalsto the apparatus 1806. In some aspects, the transmission component 1804may include one or more antennas, a modulator, a transmit MIMOprocessor, a transmit processor, a controller/processor, a memory, or acombination thereof, of the base station described above in connectionwith FIG. 2 . In some aspects, the transmission component 1804 may beco-located with the reception component 1802 in a transceiver.

The reception component 1802 and/or the transmission component 1804 maycommunicate, with a relay UE and a remote UE, configuration informationfor an adaptation layer of a sidelink signaling interface between therelay UE and the remote UE, the configuration information including atleast one of a remote UE identifier for the remote UE identifying asidelink unicast link between the remote UE and the relay UE for a relayservice, bearer identifier information identifying one or more bearersbetween the remote UE and the network entity associated with the relayservice, RLC channel mapping information, wherein the RLC channelmapping information includes a mapping between a bearer identifier andone or more RLC channels of a sidelink unicast link and one or more RLCchannels of a link with the relay UE, or data routing informationassociated with the relay service. The reception component 1802 and/orthe transmission component 1804 may communicate with the remote UE viathe relay UE based at least in part on the configuration information.

The number and arrangement of components shown in FIG. 18 are providedas an example. In practice, there may be additional components, fewercomponents, different components, or differently arranged componentsthan those shown in FIG. 18 . Furthermore, two or more components shownin FIG. 18 may be implemented within a single component, or a singlecomponent shown in FIG. 18 may be implemented as multiple, distributedcomponents. Additionally, or alternatively, a set of (one or more)components shown in FIG. 18 may perform one or more functions describedas being performed by another set of components shown in FIG. 18 .

FIG. 19 is a block diagram of an example apparatus 1900 for wirelesscommunication. The apparatus 1900 may be a remote UE, or a remote UE mayinclude the apparatus 1900. In some aspects, the apparatus 1900 includesa reception component 1902 and a transmission component 1904, which maybe in communication with one another (for example, via one or more busesand/or one or more other components). As shown, the apparatus 1900 maycommunicate with another apparatus 1906 (such as a UE, a base station,or another wireless communication device) using the reception component1902 and the transmission component 1904. As further shown, theapparatus 1900 may include a determination component 1908, among otherexamples.

In some aspects, the apparatus 1900 may be configured to perform one ormore operations described herein in connection with FIGS. 7-13 .Additionally, or alternatively, the apparatus 1900 may be configured toperform one or more processes described herein, such as process 1600 ofFIG. 16 , or a combination thereof. In some aspects, the apparatus 1900and/or one or more components shown in FIG. 19 may include one or morecomponents of the UE described above in connection with FIG. 2 .Additionally, or alternatively, one or more components shown in FIG. 19may be implemented within one or more components described above inconnection with FIG. 2 . Additionally, or alternatively, one or morecomponents of the set of components may be implemented at least in partas software stored in a memory. For example, a component (or a portionof a component) may be implemented as instructions or code stored in anon-transitory computer-readable medium and executable by a controlleror a processor to perform the functions or operations of the component.

The reception component 1902 may receive communications, such asreference signals, control information, data communications, or acombination thereof, from the apparatus 1906. The reception component1902 may provide received communications to one or more other componentsof the apparatus 1900. In some aspects, the reception component 1902 mayperform signal processing on the received communications (such asfiltering, amplification, demodulation, analog-to-digital conversion,demultiplexing, deinterleaving, de-mapping, equalization, interferencecancellation, or decoding, among other examples), and may provide theprocessed signals to the one or more other components of the apparatus1906. In some aspects, the reception component 1902 may include one ormore antennas, a demodulator, a MIMO detector, a receive processor, acontroller/processor, a memory, or a combination thereof, of the UEdescribed above in connection with FIG. 2 .

The transmission component 1904 may transmit communications, such asreference signals, control information, data communications, or acombination thereof, to the apparatus 1906. In some aspects, one or moreother components of the apparatus 1906 may generate communications andmay provide the generated communications to the transmission component1904 for transmission to the apparatus 1906. In some aspects, thetransmission component 1904 may perform signal processing on thegenerated communications (such as filtering, amplification, modulation,digital-to-analog conversion, multiplexing, interleaving, mapping, orencoding, among other examples), and may transmit the processed signalsto the apparatus 1906. In some aspects, the transmission component 1904may include one or more antennas, a modulator, a transmit MIMOprocessor, a transmit processor, a controller/processor, a memory, or acombination thereof, of the UE described above in connection with FIG. 2. In some aspects, the transmission component 1904 may be co-locatedwith the reception component 1902 in a transceiver.

The reception component 1902 and/or the transmission component 1904 mayestablish a sidelink unicast link with a relay UE via a sidelinksignaling interface. The reception component 1902 may receiveconfiguration information for an adaptation layer of the sidelinksignaling interface, the configuration information including at leastone of a remote UE identifier for the remote UE identifying the sidelinkunicast link between the remote UE and the relay UE for a relay service,bearer identifier information identifying one or more bearers betweenthe remote UE and a network entity associated with the relay service, orRLC channel mapping information, wherein the RLC channel mappinginformation includes a mapping between a bearer identifier and one ormore RLC channels of the sidelink unicast link and one or more RLCchannels of a link with the network entity. The reception component 1902and/or the transmission component 1904 may communicate with the networkentity via the relay UE based at least in part on the configurationinformation.

The number and arrangement of components shown in FIG. 19 are providedas an example. In practice, there may be additional components, fewercomponents, different components, or differently arranged componentsthan those shown in FIG. 19 . Furthermore, two or more components shownin FIG. 19 may be implemented within a single component, or a singlecomponent shown in FIG. 19 may be implemented as multiple, distributedcomponents. Additionally, or alternatively, a set of (one or more)components shown in FIG. 19 may perform one or more functions describedas being performed by another set of components shown in FIG. 19 .

The following provides an overview of some aspects of the presentdisclosure:

Aspect 1: A method of wireless communication performed by a relay userequipment (UE), comprising: establishing a sidelink unicast link with aremote UE via a sidelink signaling interface; identifying configurationinformation for an adaptation layer of the sidelink signaling interface,the configuration information including at least one of: a remote UEidentifier for the remote UE identifying the sidelink unicast linkbetween the remote UE and the relay UE for a relay service, beareridentifier information identifying one or more bearers between theremote UE and a network entity associated with the relay service, radiolink control (RLC) channel mapping information, wherein the RLC channelmapping information includes a mapping between a bearer identifier andone or more RLC channels of the sidelink unicast link and one or moreRLC channels of a link with the network entity, or data routinginformation associated with the relay service; and relayingcommunications between the remote UE and the network entity based atleast in part on the configuration information for the adaptation layerof the sidelink signaling interface.

Aspect 2: The method of aspect 1, wherein the sidelink signalinginterface is a ProSe sidelink (PC5) interface and the link with thenetwork entity is via a Uu interface.

Aspect 3: The method of any of aspects 1-2, wherein relayingcommunications between the remote UE and the network entity is based atleast in part on a sidelink signaling interface adaptation layer header,wherein the sidelink signaling interface adaptation layer headerindicates at least one of: the remote UE identifier of the remote UE, abearer identifier of a bearer between the remote UE and a network entityassociated with the relay service, or a path identifier for the datarouting associated with the relay service.

Aspect 4: The method of any of aspects 1-3, wherein the remote UEidentifier corresponds to a unique index assigned to each remote UE, ofa plurality of remote UEs, in communication with the relay UE viarespective sidelink unicast links.

Aspect 5: The method of any of aspects 1-4, further comprising:assigning remote UE identifiers to each remote UE, of a plurality ofremote UEs, in communication with the relay UE.

Aspect 6: The method of any of aspects 1-5, wherein establishing thesidelink unicast link with the remote UE comprises: assigning the remoteUE identifier to the remote UE including a unique index associated withthe sidelink unicast link; and transmitting, to the remote UE, anindication of the remote UE identifier via a sidelink signalinginterface message.

Aspect 7: The method of any of aspects 1-6, further comprising:assigning a unique index associated with the sidelink unicast link; andtransmitting information indicating the unique index to the networkentity via a radio resource control message.

Aspect 8: The method of any of aspects 1-7, wherein identifying theconfiguration information comprises: receiving, from the network entity,a relaying configuration indicating at least part of the configurationinformation.

Aspect 9: The method of any of aspects 1-4, wherein identifying theconfiguration information comprises: receiving, from the network entity,an indication of the remote UE identifier via a radio resource controlmessage.

Aspect 10: The method of aspect 9, wherein receiving, from the networkentity, the indication of the remote UE identifier comprises: receiving,from the network entity, an indication of remote UE identifiers for eachremote UE, of a plurality of remote UEs, in communication with the relayUE.

Aspect 11: The method of any of aspects 9-10, wherein receiving, fromthe network entity, the indication of the remote UE identifiercomprises: receiving, from the network entity, an indication of a cellradio network temporary identifier (C-RNTI) for each remote UE, of aplurality of remote UEs, in communication with the relay UE.

Aspect 12: The method of any of aspects 9-10, wherein receiving, fromthe network entity, the indication of the remote UE identifiercomprises: receiving, from the network entity, an indication of atemporary identifier for each remote UE, of a plurality of remote UEs,in communication with the relay UE, wherein the temporary identifier isunique among the plurality of remote UEs in communication with the relayUE.

Aspect 13: The method of any of aspects 1-12, wherein identifying theconfiguration information comprises: receiving, from the network entity,the bearer identifier information including an indication of a beareridentifier identifying a bearer between the remote UE and the networkentity associated with the relay service, wherein the bearer identifieris the same as a data radio bearer (DRB) identifier of a DRB between theremote UE and the network entity or the same as a signaling radio bearer(SRB) identifier of an SRB between the remote UE and the network entity.

Aspect 14: The method of any of aspects 1-12, wherein identifying theconfiguration information comprises: receiving, from the network entity,the bearer identifier information including an indication of a beareridentifier identifying a bearer between the remote UE and the networkentity associated with the relay service, wherein the bearer identifieris a unique identifier associated with the bearer between the remote UEand the network entity to be used with the relay service.

Aspect 15: The method of any of aspects 1-14, wherein identifying theconfiguration information comprises: receiving, from the network entity,an indication of a default bearer identifier identifying a signalingradio bearer (SRB) associated with radio resource control messages.

Aspect 16: The method of aspect 15, further comprising: receiving, fromthe remote UE via the sidelink unicast link, a radio resource controlsetup request message, wherein the radio resource control setup requestmessage includes the default bearer identifier; determining that theradio resource control setup request message is to be transmitted usingthe SRB associated with radio resource control messages based at leastin part on the default bearer identifier; and relaying the radioresource control setup request message to the network entity via an RLCchannel for the SRB associated with radio resource control messages.

Aspect 17: The method of aspect 16, further comprising: receiving, fromthe network entity, a relaying configuration via a radio resourcecontrol message indicating the bearer identifier based at least in parton relaying the radio resource control setup request message to thenetwork entity; and relaying the radio resource control messageindicating the bearer identifier to the remote UE based at least in parton the relaying configuration.

Aspect 18: The method of any of aspects 1-17, wherein relayingcommunications between the remote UE and the network entity comprises:receiving, from the remote UE via the sidelink unicast link, a packetdata convergence protocol (PDCP) packet data unit (PDU) that includes anadaptation layer header that indicates at least one of: the remote UEidentifier associated with the remote UE, or a bearer identifier;identifying an RLC channel of the link with the network entity based atleast in part on the RLC channel mapping information and the beareridentifier; generating a Uu PDCP PDU for the link with the networkentity that includes an adaptation layer header that indicates at leastone of: the remote UE identifier associated with the remote UE, or thebearer identifier; and transmitting, to the network entity via the RLCchannel, the Uu PDCP PDU for the link with the network entity thatincludes the adaptation layer header.

Aspect 19: The method of any of aspects 1-18, wherein relayingcommunications between the remote UE and the network entity comprises:receiving, from the network entity, a Uu packet data convergenceprotocol (PDCP) packet data unit (PDU) that includes an adaptation layerheader that indicates at least one of: the remote UE identifierassociated with the remote UE, or a bearer identifier; identifying anRLC channel of the sidelink unicast link based at least in part on theRLC channel mapping information and the bearer identifier; generating aPDCP PDU for the sidelink unicast link that includes an adaptation layerheader that indicates at least one of: the remote UE identifierassociated with the remote UE, or the bearer identifier; andtransmitting, to the remote UE via the RLC channel, the PDCP PDU for thesidelink unicast link that includes the adaptation layer header.

Aspect 20: The method of any of aspects 1-19, further comprising:performing a privacy update procedure with at least one of the remote UEor the network entity, wherein the privacy update procedure includesupdating information included in configuration information.

Aspect 21: The method of aspect 20, wherein performing the privacyupdate procedure comprises: performing the privacy update procedureaccording to a periodic schedule.

Aspect 22: The method of any of aspects 20-21, wherein performing theprivacy update procedure comprises: detecting a trigger event associatedwith a privacy update; and performing the privacy update procedure basedat least in part on detecting the trigger event.

Aspect 23: The method of any of aspects 20-22, wherein performing theprivacy update procedure comprises: modifying the remote UE identifierfor the remote UE to a modified remote UE identifier; communicating,with the remote UE via the sidelink unicast link, to indicate themodified remote UE identifier; and communicating, with the networkentity, to indicate the modified remote UE identifier.

Aspect 24: The method of any of aspects 20-23, wherein performing theprivacy update procedure comprises: receiving, from the network entity,an indication of a modified RLC channel identifier for the sidelinksignaling interface via a radio resource control message; modifying aprevious RLC channel identifier for the sidelink signaling interface tothe modified RLC channel identifier; communicating, with the remote UEvia the sidelink unicast link, to indicate the modified RLC channelidentifier; and communicating, with the network entity, to indicate thatthe RLC channel identifier for the sidelink signaling interface has beenmodified at the relay UE and the remote UE based at least in part oncommunicating with the remote UE to indicate the modified RLC channelidentifier.

Aspect 25: The method of any of aspects 20-22, wherein performing theprivacy update procedure comprises: receiving, from the network entity,an indication of a modified remote UE identifier for the remote UE;modifying the remote UE identifier for the remote UE to the modifiedremote UE identifier; communicating, with the remote UE via the sidelinkunicast link, to indicate the modified remote UE identifier; andcommunicating, with the network entity, to indicate that the remote UEidentifier has been modified at the relay UE and the remote UE based atleast in part on communicating with the remote UE to indicate themodified remote UE identifier.

Aspect 26: The method of any of aspects 20-25, wherein performing theprivacy update procedure comprises: receiving, from the network entity,an indication of a modified bearer identifier for a bearer between theremote UE and a network entity associated with the relay service;modifying a previous bearer identifier for the bearer to the modifiedbearer identifier; and relaying, from the network entity and to theremote UE, an indication of the modified bearer identifier.

Aspect 27: The method of aspect 26, further comprising: receiving, fromthe remote UE, a signal that includes an indication of the previousbearer identifier for the bearer in an adaptation layer header of thesignal after receiving the indication of the modified bearer identifierand prior to receiving a signal that include an indication of themodified bearer identifier; identifying an RLC channel of the link withthe network entity based at least in part on the RLC channel mappinginformation and the previous bearer identifier; generating a signal forthe link with the network entity that includes an indication of theprevious bearer identifier; and transmitting, to the network entity viathe RLC channel, the signal for the link with the network entity thatincludes the indication of the previous bearer identifier.

Aspect 28: The method of any of aspects 26-27, further comprising:receiving, from the remote UE or the network entity, a signal thatincludes an indication of the modified bearer identifier in anadaptation layer header of the signal; and refraining from relayingcommunications using the previous bearer identifier based at least inpart on receiving the signal that includes the indication of themodified bearer identifier in the adaptation layer header of the signal.

Aspect 29: The method of aspect 20, wherein performing the privacyupdate procedure comprises: receiving, from the network entity, anindication of modified identifier information for at least one of theadaptation layer of the sidelink signaling interface or the adaptionlayer of the link with the network entity; modifying the configurationinformation based at least in part on the modified identifierinformation; communicating, with the remote UE via the sidelink unicastlink, to indicate the modified identifier information; andcommunicating, with the network entity, to indicate that theconfiguration information for the sidelink signaling interface has beenmodified at the relay UE and the remote UE based at least in part oncommunicating with the remote UE to indicate the modified identifierinformation.

Aspect 30: The method of aspect 29, further comprising: receiving, fromthe remote UE, a signal that includes a previous identifier, that ismodified by the modified identifier information to a modifiedidentifier, in an adaptation layer header of the signal after receivingthe indication of the modified identifier information and prior toreceiving a signal that includes an indication of the modifiedidentifier; and relaying, to the network entity via an RLC channel, thesignal based at least in part on the previous identifier.

Aspect 31: The method of aspect 29: further comprising: receiving, fromthe remote UE or the network entity, a signal that includes anindication of a modified identifier, indicated in the modifiedidentifier information, in an adaptation layer header of the signal; andrefraining from relaying communications using a previous identifierbased at least in part on receiving the signal that includes theindication of the modified identifier in the adaptation layer header ofthe signal.

Aspect 32: A method of wireless communication performed by a networkentity, comprising: communicating, with a relay user equipment (UE) anda remote UE, configuration information for an adaptation layer of asidelink signaling interface between the relay UE and the remote UE, theconfiguration information including at least one of: a remote UEidentifier for the remote UE identifying a sidelink unicast link betweenthe remote UE and the relay UE for a relay service, bearer identifierinformation identifying one or more bearers between the remote UE and anetwork entity associated with the relay service, radio link control(RLC) channel mapping information, wherein the RLC channel mappinginformation includes a mapping between a bearer identifier and one ormore RLC channels of a sidelink unicast link and one or more RLCchannels of a link with the relay UE, or data routing informationassociated with the relay service; and communicating with the remote UEvia the relay UE based at least in part on the configurationinformation.

Aspect 33: The method of aspect 32, wherein the sidelink signalinginterface is a ProSe sidelink (PC5) interface and the link with therelay UE is via a Uu interface.

Aspect 34: The method of any of aspects 32-33, wherein the remote UEidentifier corresponds to a unique index assigned to each remote UE, ofa plurality of remote UEs, in communication with the relay UE viarespective sidelink unicast links.

Aspect 35: The method of any of aspects 32-34, wherein communicating theconfiguration information comprises: receiving, from the relay UE, anindication of remote UE identifiers for each remote UE, of a pluralityof remote UEs, in communication with the relay UE via a radio resourcecontrol message.

Aspect 36: The method of any of aspects 32-34, further comprising:assigning remote UE identifiers to each remote UE, of a plurality ofremote UEs, in communication with the relay UE.

Aspect 37: The method of aspect 36, wherein assigning remote UEidentifiers to each remote UE, of the plurality of remote UEs, incommunication with the relay UE comprises: assigning, for a remote UE ofthe plurality of remote UEs, the remote UE identifier as a cell radionetwork temporary identifier (C-RNTI) identifying a sidelink unicastlink between the remote UE and the relay UE.

Aspect 38: The method of aspect 36, wherein assigning remote UEidentifiers to each remote UE, of the plurality of remote UEs, incommunication with the relay UE comprises: assigning, for a remote UE ofthe plurality of remote UEs, a temporary identifier for the remote UE,wherein the temporary identifier is unique among the plurality of remoteUEs in communication with the relay UE.

Aspect 39: The method of any of aspects 36-38, further comprising:transmitting, to the remote UE via the relay UE, an indication of theremote UE identifier for the remote UE via a radio resource controlmessage.

Aspect 40: The method of any of aspects 36-39, wherein communicating theconfiguration information comprises: transmitting, to the relay UE, arelaying configuration via a radio resource control message, wherein therelaying configuration indicates the remote UE identifiers for eachremote UE, of the plurality of remote UEs, in communication with therelay UE.

Aspect 41: The method of any of aspects 32-40, further comprising:assigning a bearer identifier for each bearer of the one or more bearersbetween the remote UE and a network entity associated with the relayservice.

Aspect 42: The method of aspect 41, wherein a bearer identifier for abearer, of the one or more bearers, is same as a data radio bearer (DRB)identifier of a DRB between the remote UE and the network entity or thesame as a signaling radio bearer (SRB) identifier of an SRB between theremote UE and the network entity.

Aspect 43: The method of aspect 41, wherein a bearer identifier for abearer, of the one or more bearers, is a unique identifier associatedwith the bearer between the remote UE and the network entity to be usedwith the relay service.

Aspect 44: The method of any of aspects 41-43, further comprising:transmitting, to the remote UE via the relay UE, the bearer identifierinformation via a radio resource control message, wherein the beareridentifier information indicates: the bearer identifier for each bearerof the one or more bearers between the remote UE and a network entityassociated with the relay service, and for each bearer identifier, anindication of a data radio bearer (DRB) or a signaling radio bearer(SRB) associated with the bearer identifier.

Aspect 45: The method of any of aspects 41-44, wherein communicating theconfiguration information comprises: transmitting, to the relay UE, thebearer identifier information via a radio resource control message,wherein the bearer identifier information indicates: the beareridentifier for each bearer of the one or more bearers between the remoteUE and a network entity associated with the relay service, and for eachbearer identifier, an indication of a data radio bearer (DRB) or asignaling radio bearer (SRB) associated with the bearer identifier.

Aspect 46: The method of any of aspects 32-45, wherein communicating theconfiguration information comprises: transmitting, to the relay UE andthe remote UE via the relay UE, an indication of a default beareridentifier identifying a signaling radio bearer (SRB) associated withradio resource control messages.

Aspect 47: The method of aspect 46, wherein the SRB associated withradio resource control messages is SRB0.

Aspect 48: The method of any of aspects 32-47, wherein communicatingwith the remote UE via the relay UE comprises: receiving, from the relayUE, an adaptation layer protocol data unit (PDU); determining asignaling radio bearer (SRB) or data radio bearer (DRB) associated withthe remote UE based at least in part on a header of the adaptation layerPDU; removing the header of the adaptation layer PDU; and transferring aNew Radio packet data convergence protocol (PDCP) PDU of the adaptationlayer PDU to an upper layer.

Aspect 49: The method of any of aspects 32-48, wherein communicatingwith the remote UE via the relay UE comprises: determining the remote UEidentifier of the remote UE associated with a sidelink unicast link forthe remote UE; determining a bearer identifier of the remote UEcorresponding to a radio access bearer of the remote UE; determining aradio access RLC channel between the relay UE and the network entitycorresponding to the bearer identifier; generating an adaptation layerheader including at least one of the remote UE identifier, the beareridentifier, or a path identifier; and transmitting, to the relay UE, anadaptation layer protocol data unit (PDU) with the adaptation layerheader on the radio access RLC channel between the relay UE and thenetwork entity.

Aspect 50: The method of any of aspects 32-49, further comprising:performing a privacy update procedure with at least one of the remote UEor the relay UE, wherein the privacy update procedure includes updatinginformation included in configuration information.

Aspect 51: The method of aspect 50, wherein performing the privacyupdate procedure comprises: performing the privacy update procedureaccording to a periodic schedule.

Aspect 52: The method of any of aspects 50-51, wherein performing theprivacy update procedure comprises: detecting a trigger event associatedwith a privacy update; and performing the privacy update procedure basedat least in part on detecting the trigger event.

Aspect 53: The method of any of aspects 50-52, wherein performing theprivacy update procedure comprises: modifying the remote UE identifierfor the remote UE to a modified remote UE identifier; communicating,with the remote UE via the relay UE, to indicate the modified remote UEidentifier; and communicating, with the relay UE, to indicate themodified remote UE identifier.

Aspect 54: The method of any of aspects 50-53, wherein performing theprivacy update procedure comprises: modifying a previous RLC channelidentifier for the sidelink signaling interface between the relay UE andthe remote UE to a modified RLC channel identifier; transmitting, to therelay UE and the remote UE via the relay UE, an indication of themodified RLC channel identifier for the sidelink signaling interface viaa radio resource control message; and receiving, from the relay UE, anindication that the RLC channel identifier for the sidelink signalinginterface has been modified at the relay UE and the remote UE.

Aspect 55: The method of any of aspects 50-52, wherein performing theprivacy update procedure comprises: receiving, from the relay UE, anindication of a modified remote UE identifier for the remote UE;modifying the remote UE identifier for the remote UE to the modifiedremote UE identifier; and receiving, from the relay UE, an indicationthat the remote UE identifier has been modified at the relay UE and theremote UE.

Aspect 56: The method of any of aspects 50-55, wherein performing theprivacy update procedure comprises: modifying a previous beareridentifier for a bearer between the remote UE and the network entityassociated with the relay service to a modified bearer identifier;transmitting, to the relay UE and the remote UE via the relay UE, anindication of the modified bearer identifier for a bearer between theremote UE and a network entity associated with the relay service; andreceiving, from the relay UE, an indication that the bearer identifierhas been modified at the relay UE and the remote UE.

Aspect 57: The method of aspect 50, wherein performing the privacyupdate procedure comprises: modifying one or more identifiers for anadaption layer header for the relay service; communicating, with theremote UE via the relay UE, to indicate modified identifier informationthat indicates the one or more modified identifiers; and communicating,with the relay UE, to indicate the modified identifier information thatindicates the one or more modified identifier.

Aspect 58: A method of wireless communication performed by a remote userequipment (UE), comprising: establishing a sidelink unicast link with arelay UE via a sidelink signaling interface; receiving configurationinformation for an adaptation layer of the sidelink signaling interface,the configuration information including at least one of: a remote UEidentifier for the remote UE identifying the sidelink unicast linkbetween the remote UE and the relay UE for a relay service, beareridentifier information identifying one or more bearers between theremote UE and a network entity associated with the relay service, orradio link control (RLC) channel mapping information, wherein the RLCchannel mapping information includes a mapping between the beareridentifier and one or more RLC channels of the sidelink unicast link andone or more RLC channels of a link with the network entity; andcommunicating with the network entity via the relay UE based at least inpart on the configuration information.

Aspect 59: The method of aspect 58, wherein the sidelink signalinginterface is a ProSe sidelink (PC5) interface and the link with thenetwork entity is via a Uu interface.

Aspect 60: The method of any of aspects 58-59, wherein the remote UEidentifier corresponds to a unique index assigned to the remote UE.

Aspect 61: The method of any of aspects 58-60, wherein receiving theconfiguration information comprises: receiving, from the relay UE, anindication of the remote UE identifier for the remote UE.

Aspect 62: The method of any of aspects 58-60, wherein receiving theconfiguration information comprises: receiving, from the network entityvia the relay UE, an indication of the remote UE identifier for theremote UE via a radio resource control message.

Aspect 63: The method of aspect 62, wherein the remote UE identifier isthe same as a cell radio network temporary identifier (C-RNTI)identifying the sidelink unicast link between the remote UE and therelay UE.

Aspect 64: The method of aspect 62, wherein the remote UE identifier isa temporary identifier for the remote UE, wherein the temporaryidentifier is unique among a plurality of remote UEs in communicationwith the relay UE.

Aspect 65: The method of any of aspects 58-64, further comprising:receiving, from the network entity via the relay UE, the beareridentifier information via a radio resource control message, wherein thebearer identifier information indicates: the bearer identifier for eachbearer of the one or more bearers between the remote UE and a networkentity associated with the relay service, and for each beareridentifier, an indication of a data radio bearer (DRB) or a signalingradio bearer (SRB) associated with the bearer identifier.

Aspect 66: The method of any of aspects 58-65, wherein receiving theconfiguration information comprises: receiving, from the network entityvia the relay UE, an indication of a default bearer identifieridentifying a signaling radio bearer (SRB) associated with radioresource control messages.

Aspect 67: The method of aspect 66, wherein the SRB associated withradio resource control messages is SRB0.

Aspect 68: The method of any of aspects 66-67, further comprising:transmitting, to the network entity via the relay UE, a resource controlmessage including the default bearer identifier identifying the SRBassociated with radio resource control messages.

Aspect 69: The method of any of aspects 58-68, wherein communicatingwith the network entity via the relay UE comprises: receiving, from therelay UE, an adaptation layer protocol data unit (PDU); determining asignaling radio bearer (SRB) or data radio bearer (DRB) associated withthe remote UE based at least in part on a header of the adaptation layerPDU; removing the header of the adaptation layer PDU; and transferring aNew Radio packet data convergence protocol (PDCP) PDU of the adaptationlayer PDU to an upper layer.

Aspect 70: The method of any of aspects 58-69, wherein communicatingwith the network entity via the relay UE comprises: determining theremote UE identifier of the remote UE associated with the sidelinkunicast link for the remote UE; determining a bearer identifier of theremote UE corresponding to a radio access bearer of the remote UE;determining a sidelink RLC channel between the relay UE and the remoteUE corresponding to the bearer identifier; generating an adaptationlayer header including at least one of the remote UE identifier, thebearer identifier, or a path identifier; and transmitting, to the relayUE, an adaptation layer protocol data unit (PDU) with the adaptationlayer header on the sidelink RLC channel between the relay UE and theremote UE.

Aspect 71: The method of any of aspects 58-70, further comprising:performing a privacy update procedure with at least one of the networkentity or the relay UE, wherein the privacy update procedure includesupdating information included in configuration information.

Aspect 72: The method of aspect 71, wherein performing the privacyupdate procedure comprises: performing the privacy update procedureaccording to a periodic schedule.

Aspect 73: The method of any of aspects 71-72, wherein performing theprivacy update procedure comprises: detecting a trigger event associatedwith a privacy update; and performing the privacy update procedure basedat least in part on detecting the trigger event.

Aspect 74: The method of any of aspects 71-73, wherein performing theprivacy update procedure comprises: receiving, from the network entityvia the relay UE, an indication of a modified remote UE identifier;modifying a previous remote UE identifier for the remote UE to amodified remote UE identifier; and communicating, with the relay UE, toindicate that the remote UE identifier has been modified.

Aspect 75: The method of any of aspects 71-73, wherein performing theprivacy update procedure comprises: receiving, from the relay UE, anindication of a modified remote UE identifier for the remote UE;modifying the remote UE identifier for the remote UE to the modifiedremote UE identifier; and transmitting, to the relay UE, an indicationthat the remote UE identifier has been modified at the remote UE.

Aspect 76: The method of any of aspects 71-75, wherein performing theprivacy update procedure comprises: receiving, from the network entityvia the relay UE, an indication of a modified bearer identifier for abearer between the remote UE and a network entity associated with therelay service; modifying a previous bearer identifier for the bearer tothe modified bearer identifier; and communicating, with the networkentity via the remote UE, using the modified bearer identifier.

Aspect 77: The method of aspect 71, wherein performing the privacyupdate procedure comprises: receiving, from the network entity via therelay UE or from the relay UE, an indication of modified identifierinformation indicating one or more modified identifiers for theadaptation layer; modifying the configuration information based at leastin part on the modified identifier information; and communicating, withthe relay UE, to indicate that the one or more modified identifiers forthe adaptation layer been modified at the remote UE.

Aspect 78: An apparatus for wireless communication at a device,comprising a processor; memory coupled with the processor; andinstructions stored in the memory and executable by the processor tocause the apparatus to perform the method of one or more aspects ofaspects 1-31.

Aspect 79: A device for wireless communication, comprising a memory andone or more processors coupled to the memory, the memory and the one ormore processors configured to perform the method of one or more aspectsof aspects 1-31.

Aspect 80: An apparatus for wireless communication, comprising at leastone means for performing the method of one or more aspects of aspects1-31.

Aspect 81: A non-transitory computer-readable medium storing code forwireless communication, the code comprising instructions executable by aprocessor to perform the method of one or more aspects of aspects 1-31.

Aspect 82: A non-transitory computer-readable medium storing a set ofinstructions for wireless communication, the set of instructionscomprising one or more instructions that, when executed by one or moreprocessors of a device, cause the device to perform the method of one ormore aspects of aspects 1-31.

Aspect 83: An apparatus for wireless communication at a device,comprising a processor; memory coupled with the processor; andinstructions stored in the memory and executable by the processor tocause the apparatus to perform the method of one or more aspects ofaspects 32-57.

Aspect 84: A device for wireless communication, comprising a memory andone or more processors coupled to the memory, the memory and the one ormore processors configured to perform the method of one or more aspectsof aspects 32-57.

Aspect 85: An apparatus for wireless communication, comprising at leastone means for performing the method of one or more aspects of aspects32-57.

Aspect 86: A non-transitory computer-readable medium storing code forwireless communication, the code comprising instructions executable by aprocessor to perform the method of one or more aspects of aspects 32-57.

Aspect 87: A non-transitory computer-readable medium storing a set ofinstructions for wireless communication, the set of instructionscomprising one or more instructions that, when executed by one or moreprocessors of a device, cause the device to perform the method of one ormore aspects of aspects 32-57.

Aspect 88: An apparatus for wireless communication at a device,comprising a processor; memory coupled with the processor; andinstructions stored in the memory and executable by the processor tocause the apparatus to perform the method of one or more aspects ofaspects 58-77.

Aspect 89: A device for wireless communication, comprising a memory andone or more processors coupled to the memory, the memory and the one ormore processors configured to perform the method of one or more aspectsof aspects 58-77.

Aspect 90: An apparatus for wireless communication, comprising at leastone means for performing the method of one or more aspects of aspects58-77.

Aspect 91: A non-transitory computer-readable medium storing code forwireless communication, the code comprising instructions executable by aprocessor to perform the method of one or more aspects of aspects 58-77.

Aspect 92: A non-transitory computer-readable medium storing a set ofinstructions for wireless communication, the set of instructionscomprising one or more instructions that, when executed by one or moreprocessors of a device, cause the device to perform the method of one ormore aspects of aspects 58-77.

The foregoing disclosure provides illustration and description, but isnot intended to be exhaustive or to limit the aspects to the preciseforms disclosed. Modifications and variations may be made in light ofthe above disclosure or may be acquired from practice of the aspects.

As used herein, the term “component” is intended to be broadly construedas hardware and/or a combination of hardware and software. “Software”shall be construed broadly to mean instructions, instruction sets, code,code segments, program code, programs, subprograms, software modules,applications, software applications, software packages, routines,subroutines, objects, executables, threads of execution, procedures,and/or functions, among other examples, whether referred to as software,firmware, middleware, microcode, hardware description language, orotherwise. As used herein, a processor is implemented in hardware and/ora combination of hardware and software. It will be apparent that systemsand/or methods described herein may be implemented in different forms ofhardware and/or a combination of hardware and software. The actualspecialized control hardware or software code used to implement thesesystems and/or methods is not limiting of the aspects. Thus, theoperation and behavior of the systems and/or methods were describedherein without reference to specific software code—it being understoodthat software and hardware can be designed to implement the systemsand/or methods based, at least in part, on the description herein.

As used herein, satisfying a threshold may, depending on the context,refer to a value being greater than the threshold, greater than or equalto the threshold, less than the threshold, less than or equal to thethreshold, equal to the threshold, not equal to the threshold, or thelike.

Even though particular combinations of features are recited in theclaims and/or disclosed in the specification, these combinations are notintended to limit the disclosure of various aspects. In fact, many ofthese features may be combined in ways not specifically recited in theclaims and/or disclosed in the specification. Although each dependentclaim listed below may directly depend on only one claim, the disclosureof various aspects includes each dependent claim in combination withevery other claim in the claim set. As used herein, a phrase referringto “at least one of” a list of items refers to any combination of thoseitems, including single members. As an example, “at least one of a, b,or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well asany combination with multiples of the same element (e.g., a-a, a-a-a,a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or anyother ordering of a, b, and c).

No element, act, or instruction used herein should be construed ascritical or essential unless explicitly described as such. Also, as usedherein, the articles “a” and “an” are intended to include one or moreitems and may be used interchangeably with “one or more.” Further, asused herein, the article “the” is intended to include one or more itemsreferenced in connection with the article “the” and may be usedinterchangeably with “the one or more.” Furthermore, as used herein, theterms “set” and “group” are intended to include one or more items (e.g.,related items, unrelated items, or a combination of related andunrelated items), and may be used interchangeably with “one or more.”Where only one item is intended, the phrase “only one” or similarlanguage is used. Also, as used herein, the terms “has,” “have,”“having,” or the like are intended to be open-ended terms. Further, thephrase “based on” is intended to mean “based, at least in part, on”unless explicitly stated otherwise. Also, as used herein, the term “or”is intended to be inclusive when used in a series and may be usedinterchangeably with “and/or,” unless explicitly stated otherwise (e.g.,if used in combination with “either” or “only one of”).

1. A method of wireless communication performed by a relay userequipment (UE), comprising: establishing a sidelink unicast link with aremote UE via a sidelink signaling interface; identifying configurationinformation for an adaptation layer of the sidelink signaling interface,the configuration information including at least one of: a remote UEidentifier for the remote UE identifying the sidelink unicast linkbetween the remote UE and the relay UE for a relay service, beareridentifier information identifying one or more bearers between theremote UE and a network entity associated with the relay service, radiolink control (RLC) channel mapping information, wherein the RLC channelmapping information includes a mapping between a bearer identifier andone or more RLC channels of the sidelink unicast link and one or moreRLC channels of a link with the network entity, or data routinginformation associated with the relay service; and relayingcommunications between the remote UE and the network entity based atleast in part on the configuration information for the adaptation layerof the sidelink signaling interface.
 2. The method of claim 1, whereinthe sidelink signaling interface is a ProSe sidelink (PC5) interface andthe link with the network entity is via a Uu interface.
 3. The method ofclaim 1, wherein relaying communications between the remote UE and thenetwork entity is based at least in part on a sidelink signalinginterface adaptation layer header, wherein the sidelink signalinginterface adaptation layer header indicates at least one of: the remoteUE identifier of the remote UE, a bearer identifier of a bearer betweenthe remote UE and a network entity associated with the relay service, ora path identifier for the data routing associated with the relayservice.
 4. The method of claim 1, wherein the remote UE identifiercorresponds to a unique index assigned to each remote UE, of a pluralityof remote UEs, in communication with the relay UE via respectivesidelink unicast links.
 5. The method of claim 1, further comprising:assigning remote UE identifiers to each remote UE, of a plurality ofremote UEs, in communication with the relay UE.
 6. The method of claim1, wherein establishing the sidelink unicast link with the remote UEcomprises: assigning the remote UE identifier to the remote UE includinga unique index associated with the sidelink unicast link; andtransmitting, to the remote UE, an indication of the remote UEidentifier via a sidelink signaling interface message.
 7. The method ofclaim 1, further comprising: assigning a unique index associated withthe sidelink unicast link; and transmitting information indicating theunique index to the network entity via a radio resource control message.8. The method of claim 1, wherein identifying the configurationinformation comprises: receiving, from the network entity, a relayingconfiguration indicating at least part of the configuration information.9. The method of claim 1, wherein identifying the configurationinformation comprises: receiving, from the network entity, an indicationof the remote UE identifier via a radio resource control message. 10.The method of claim 9, wherein receiving, from the network entity, theindication of the remote UE identifier comprises: receiving, from thenetwork entity, an indication of remote UE identifiers for each remoteUE, of a plurality of remote UEs, in communication with the relay UE.11. The method of claim 9, wherein receiving, from the network entity,the indication of the remote UE identifier comprises: receiving, fromthe network entity, an indication of a cell radio network temporaryidentifier (C-RNTI) for each remote UE, of a plurality of remote UEs, incommunication with the relay UE.
 12. The method of claim 9, whereinreceiving, from the network entity, the indication of the remote UEidentifier comprises: receiving, from the network entity, an indicationof a temporary identifier for each remote UE, of a plurality of remoteUEs, in communication with the relay UE, wherein the temporaryidentifier is unique among the plurality of remote UEs in communicationwith the relay UE.
 13. The method of claim 1, wherein identifying theconfiguration information comprises: receiving, from the network entity,the bearer identifier information including an indication of a beareridentifier identifying a bearer between the remote UE and the networkentity associated with the relay service, wherein the bearer identifieris the same as a data radio bearer (DRB) identifier of a DRB between theremote UE and the network entity or the same as a signaling radio bearer(SRB) identifier of an SRB between the remote UE and the network entity.14. The method of claim 1, wherein identifying the configurationinformation comprises: receiving, from the network entity, the beareridentifier information including an indication of a bearer identifieridentifying a bearer between the remote UE and the network entityassociated with the relay service, wherein the bearer identifier is aunique identifier associated with the bearer between the remote UE andthe network entity to be used with the relay service.
 15. The method ofclaim 1, wherein identifying the configuration information comprises:receiving, from the network entity, an indication of a default beareridentifier identifying a signaling radio bearer (SRB) associated withradio resource control messages.
 16. The method of claim 15, furthercomprising: receiving, from the remote UE via the sidelink unicast link,a radio resource control setup request message, wherein the radioresource control setup request message includes the default beareridentifier; determining that the radio resource control setup requestmessage is to be transmitted using the SRB associated with radioresource control messages based at least in part on the default beareridentifier; and relaying the radio resource control setup requestmessage to the network entity via an RLC channel for the SRB associatedwith radio resource control messages.
 17. The method of claim 16,further comprising: receiving, from the network entity, a relayingconfiguration via a radio resource control message indicating the beareridentifier based at least in part on relaying the radio resource controlsetup request message to the network entity; and relaying the radioresource control message indicating the bearer identifier to the remoteUE based at least in part on the relaying configuration.
 18. The methodof claim 1, wherein relaying communications between the remote UE andthe network entity comprises: receiving, from the remote UE via thesidelink unicast link, a packet data convergence protocol (PDCP) packetdata unit (PDU) that includes an adaptation layer header that indicatesat least one of: the remote UE identifier associated with the remote UE,or a bearer identifier; identifying an RLC channel of the link with thenetwork entity based at least in part on the RLC channel mappinginformation and the bearer identifier; generating a Uu PDCP PDU for thelink with the network entity that includes an adaptation layer headerthat indicates at least one of: the remote UE identifier associated withthe remote UE, or the bearer identifier; and transmitting, to thenetwork entity via the RLC channel, the Uu PDCP PDU for the link withthe network entity that includes the adaptation layer header.
 19. Themethod of claim 1, wherein relaying communications between the remote UEand the network entity comprises: receiving, from the network entity, aUu packet data convergence protocol (PDCP) packet data unit (PDU) thatincludes an adaptation layer header that indicates at least one of: theremote UE identifier associated with the remote UE, or a beareridentifier; identifying an RLC channel of the sidelink unicast linkbased at least in part on the RLC channel mapping information and thebearer identifier; generating a PDCP PDU for the sidelink unicast linkthat includes an adaptation layer header that indicates at least one of:the remote UE identifier associated with the remote UE, or the beareridentifier; and transmitting, to the remote UE via the RLC channel, thePDCP PDU for the sidelink unicast link that includes the adaptationlayer header.
 20. The method of claim 1, further comprising: performinga privacy update procedure with at least one of the remote UE or thenetwork entity, wherein the privacy update procedure includes updatinginformation included in configuration information.
 21. The method ofclaim 20, wherein performing the privacy update procedure comprises:performing the privacy update procedure according to a periodicschedule.
 22. The method of claim 20, wherein performing the privacyupdate procedure comprises: detecting a trigger event associated with aprivacy update; and performing the privacy update procedure based atleast in part on detecting the trigger event.
 23. The method of claim20, wherein performing the privacy update procedure comprises: modifyingthe remote UE identifier for the remote UE to a modified remote UEidentifier; communicating, with the remote UE via the sidelink unicastlink, to indicate the modified remote UE identifier; and communicating,with the network entity, to indicate the modified remote UE identifier.24. The method of claim 20, wherein performing the privacy updateprocedure comprises: receiving, from the network entity, an indicationof modified identifier information for at least one of the adaptationlayer of the sidelink signaling interface or the adaption layer of thelink with the network entity; modifying the configuration informationbased at least in part on the modified identifier information;communicating, with the remote UE via the sidelink unicast link, toindicate the modified identifier information; and communicating, withthe network entity, to indicate that the configuration information forthe sidelink signaling interface has been modified at the relay UE andthe remote UE based at least in part on communicating with the remote UEto indicate the modified identifier information.
 25. The method of claim24, further comprising: receiving, from the remote UE, a signal thatincludes a previous identifier, that is modified by the modifiedidentifier information to a modified identifier, in an adaptation layerheader of the signal after receiving the indication of the modifiedidentifier information and prior to receiving a signal that includes anindication of the modified identifier; and relaying, to the networkentity via an RLC channel, the signal based at least in part on theprevious identifier.
 26. The method of claim 24, further comprising:receiving, from the remote UE or the network entity, a signal thatincludes an indication of a modified identifier, indicated in themodified identifier information, in an adaptation layer header of thesignal; and refraining from relaying communications using a previousidentifier based at least in part on receiving the signal that includesthe indication of the modified identifier in the adaptation layer headerof the signal. 27-65. (canceled)
 66. A relay user equipment (UE) forwireless communication, comprising: a memory; and one or more processorsoperatively coupled to the memory, the memory and the one or moreprocessors configured to: establish a sidelink unicast link with aremote UE via a sidelink signaling interface; identify configurationinformation for an adaptation layer of the sidelink signaling interface,the configuration information including at least one of: a remote UEidentifier for the remote UE identifying the sidelink unicast linkbetween the remote UE and the relay UE for a relay service, beareridentifier information identifying one or more bearers between theremote UE and a network entity associated with the relay service, radiolink control (RLC) channel mapping information, wherein the RLC channelmapping information includes a mapping between a bearer identifier andone or more RLC channels of the sidelink unicast link and one or moreRLC channels of a link with the network entity, or data routinginformation associated with the relay service; and relay communicationsbetween the remote UE and the network entity based at least in part onthe configuration information for the adaptation layer of the sidelinksignaling interface. 67-68. (canceled)
 69. A non-transitorycomputer-readable medium storing a set of instructions for wirelesscommunication, the set of instructions comprising: one or moreinstructions that, when executed by one or more processors of a relayuser equipment (UE), cause the relay UE to: establish a sidelink unicastlink with a remote UE via a sidelink signaling interface; identifyconfiguration information for an adaptation layer of the sidelinksignaling interface, the configuration information including at leastone of: a remote UE identifier for the remote UE identifying thesidelink unicast link between the remote UE and the relay UE for a relayservice, bearer identifier information identifying one or more bearersbetween the remote UE and a network entity associated with the relayservice, radio link control (RLC) channel mapping information, whereinthe RLC channel mapping information includes a mapping between a beareridentifier and one or more RLC channels of the sidelink unicast link andone or more RLC channels of a link with the network entity, or datarouting information associated with the relay service; and relaycommunications between the remote UE and the network entity based atleast in part on the configuration information for the adaptation layerof the sidelink signaling interface. 70-71. (canceled)
 72. An apparatusfor wireless communication, comprising: means for establishing asidelink unicast link with a remote user equipment (UE) via a sidelinksignaling interface; means for identifying configuration information foran adaptation layer of the sidelink signaling interface, theconfiguration information including at least one of: a remote UEidentifier for the remote UE identifying the sidelink unicast linkbetween the remote UE and the apparatus for a relay service, beareridentifier information identifying one or more bearers between theremote UE and a network entity associated with the relay service, radiolink control (RLC) channel mapping information, wherein the RLC channelmapping information includes a mapping between a bearer identifier andone or more RLC channels of the sidelink unicast link and one or moreRLC channels of a link with the network entity, or data routinginformation associated with the relay service; and means for relayingcommunications between the remote UE and the network entity based atleast in part on the configuration information for the adaptation layerof the sidelink signaling interface. 73-74. (canceled)